Significant Discoveries

What is a "Significant Prime"?

A significant prime is a prime that is in one of more of the following categories:

Starting on January 1st, 2018, any prime large enough to be one of the 100 largest known primes.
- Prior to January 1st, 2018, any prime number that was considered a "mega-prime", i.e., is at least one million decimal digits in length, qualified as a significant prime.
At the time of its discovery, is the largest known prime of a particular type.
Is a prime of a very rare type, of any size.

List of Significant Primes

20020 January 22 - World record Mega Prime Fermat Divisor 13*2^5523860+1 Divides F(5523858) found by Scott Brown of The United States
2020 January 21 - Generalized Fermat Mega Prime 9450844^262144+1 found by Jacob Eikelenboom of The Netherlands
2019 December 24 - Generalized Fermat Mega Prime 3214654^524288+1 found by Alen Kecic of Germany
2019 December 24 - Extended Sierpinski Problem Mega Prime 99739*2^14019102+1 found by Brian D. Niegocki of the United States
2019 December 5 - Generalized Fermat Mega Prime 9125820^262144+1 found by Yoshimitsu Kato of Japan
2019 November 6 - Generalized Fermat Mega Prime 8883864^262144+1 found by Rod Skinner of the United States
2019 September 23 - World's First AP27: 224584605939537911+81292139*23#*n for n=0..26 found by Rob Gahan of Ireland
2019 September 18 - Generalized Fermat Mega Prime 2985036^524288+1 found by Peter Harvey of the United States
2019 September 9 - Generalized Fermat Mega Prime 8521794^262144+1 found by Ken Ito of Japan
2019 September 2 - World Record Generalized Cullen Mega Prime 2805222*25^2805222+1 found by Tom Greer of the United States
2019 June 29 - Generalized Fermat Mega Prime 2877652^524288+1 found by Roman Vogt of Germany
2019 June 23 - SR5 Base 5 Mega Prime 322498*5^2800819-1 found by Jordan Romaidis of the United States
2019 June 21 - SR5 Base 5 Mega Prime 88444*5^2799269-1 found by Scott Brown of the United States
2019 April 26 - SR5 Base 5 Mega Prime 138514*5^2771922+1 found by Ken Ito of Japan
2019 April 17 - Generalized Fermat Mega Prime 2788032^524288+1 found by Ed Goforth of the Netherlands Antilles
2019 March 18 - Generalized Fermat Mega Prime 2733014^524288+1 found by Yair Givoni of Israel
2018 December 14 - Generalized Fermat Mega Prime 6291332^262144+1 found by Karsten Freihube of Germany
2018 December 12 - Generalized Fermat Mega Prime 6287774^262144+1 found by Greg Miller of the United States
2018 October 31 - World Record Generalized Fermat Mega Prime 1059094^1048576+1 found by Rob Gahan of Ireland
2018 October 11 - World Record 27121 Mega Prime 27*2^7046834+1 found by Andrew M Farrow of Australia
2018 September 26 - Generalized Fermat Mega Prime 5828034^262144+1 found by Rob Gahan of Ireland
2018 August 15 - SR5 Base 5 Mega Prime 194368*5^2638045-1 found by Honza Cholt of the Czech Republic
2018 August 4 - Generalized Fermat Mega Prime 2312092^524288+1 found by Rob Gahan of Ireland
2018 July 29 - SR5 Base 5 Mega Prime 66916*5^2628609-1 found by Honza Cholt of the Czech Republic
2018 June 20 - SR5 Base 5 Mega Prime 81556*5^2539960+1 found by Jiří Bočan of the Czech Republic
2018 June 19 - World Record SR5 Base 5 Mega Prime 327926*5^2542838-1 found by Seiya Tsuji of Japan
2018 June 17 - Generalized Fermat Mega Prime 5205422^262144+1 found by Scott Brown of the United States
2018 June 5 - Generalized Fermat Mega Prime 5152128^262144+1 found by Rob Gahan of Ireland
2018 April 3 - Extended Sierpinski Problem Prime 193997*2^11452891+1 found by Tom Greer of the United States
2018 March 21 - World Record Woodall Prime 17016602*2^17016602-1 found by Diego Bertolotti of Italy
2018 March 20 - Generalized Fermat Mega Prime 2061748^524288+1 found by Cesare Marini of Italy
2018 March 11 - World Record Generalized Cullen Mega Prime 1806676*41^1806676+1 found by Hiroyuki Okazaki of Japan
2018 March 1 - Generalized Fermat Mega Prime 4489246^262144+1 found by Wolfgang Schwieger of Germany
2018 February 15 - Generalized Fermat Mega Prime 4246258^262144+1 found by Rob Gahan of Ireland
2018 January 27 - Generalized Fermat Mega Prime 3933508^262144+1 found by Alen Kecic of Germany
2018 January 18 - World Record Generalized Cullen Mega Prime 1323365*116^1323365+1 found by Scott Brown of the United States
2018 January 15 - Generalized Fermat Mega Prime 1880370^524288+1 found by Scott Brown of the United States
2018 January 10 - Generalized Fermat Mega Prime 3853792^262144+1 found by Rod Skinner of the United States
2017 December 28 - Mega Prime 1155*2^3455254+1 found by Josh Closs of the United States
2017 December 13 - Riesel Problem Mega Prime 273809*2^8932416-1 found by Wolfgang Schwieger of Germany
2017 December 3 - Mega Prime 1065*2^3447906+1 found by Juan C. Toledo of Mexico
2017 December 3 - Generalized Fermat Mega Prime 3673932^262144+1 found by Sean Humphries of the United States
2017 November 27 - Mega Prime 1155*2^3446253+1 found by Randall Scalise of the United States
2017 November 16 - Generalized Fermat Mega Prime 3596074^262144+1 found by Howard Gordon of the United Kingdom
2017 November 13 - Mega Prime 943*2^3442990+1 found by Joshua Charles Campbell of Canada
2017 November 2 - Mega Prime 943*2^3440196+1 found by Lukáš Hron of the Czech Republic
2017 October 30 - Generalized Fermat Mega Prime 3547726^262144+1 found by Scott Brown of the United States
2017 October 29 - Mega Prime 543*2^3438810+1 found by Randall Scalise of the United States
2017 October 27 - Mega Prime 625*2^3438572+1 found by Jochen Beck of Germany
2017 October 17 - Mega Prime 1147*2^3435970+1 found by Randall Scalise of the United States
2017 October 5 - Mega Prime 911*2^3432643+1 found by Jochen Beck of Germany
2017 September 17 - Prime Sierpinski Problem Mega Prime 168451*2^19375200+1 found by Ben Maloney of Australia
2017 September 17 - World Record SR5 Base 5 Mega Prime 301562*5^2408646-1 found by Håkan Lind of Swededn
2017 September 15 - Mega Prime 1127*2^3427219+1 found by Randall Scalise of the United States
2017 September 14 - Generalized Fermat Mega Prime 47179704^131072+1 found by Andrei Okhrimouk of Australia
2017 September 5 - AP26 48277590120607451+37835074*23#*n for n=0..25 found by Bruce E. Slade of the United States
2017 August 30 - Generalized Fermat Mega Prime 47090246^131072+1 found by Roman Voskoboynikov of the United States
2017 August 29 - World Record Generalized Fermat Mega Prime 919444^1048576+1 found by Sylvanus Zimmerman of the United States
2017 August 25 - World Record SR5 Base 5 Mega Prime 171362*5^2400996-1 found by Frank Schwegler of the United States
2017 August 24 - Mega Prime 1119*2^3422189+1 found by Jochen Beck of Germany
2017 August 21 - World Record Generalized Cullen Prime 1341174*53^1341174+1 found by Hiroyuki Okazaki of Japan
2017 August 18 - Mega Prime 1005*2^3420846+1 found by Łukasz Piotrowski of Poland
2017 August 10 - Mega Prime 975*2^3419230+1 found by Eric Eskam of the United States
2017 August 9 - Mega Prime 999*2^3418885+1 found by Randall Scalise of the United States
2017 August 5 - Mega Prime 907*2^3417890+1 found by Randall Scalise of the United States
2017 July 15 - Generalized Fermat Mega Prime 46776558^131072+1 found by Giles Averay-Jones of Australia
2017 July 10 - Generalized Fermat Mega Prime 46736070^131072+1 found by Tom Greer of the United States
2017 July 9 - Generalized Fermat Mega Prime 46730280^131072+1 found by Jochen Beck of Germany
2017 June 30 - Generalized Fermat Mega Prime 3060772^262144+1 found by Sean Humphries of the United States
2017 June 20 - Mega Prime 953*2^3405729+1 found by Randall Scalise of the United States
2017 June 13 - Mega Prime 833*2^3403765+1 found by Randall Scalise of the United States
2017 June 4 - Generalized Fermat Mega Prime 46413358^131072+1 found by Sagi Iltus
2017 May 31 - Generalized Fermat Mega Prime 46385310^131072+1 found by Matt Jurach of the United States
2017 May 29 - Generalized Fermat Mega Prime 46371508^131072+1 found by Mike Kinney of the United States
2017 May 27 - Mega Prime 1167*2^3399748+1 found by Eric Eskam of the United States
2017 May 17 - Mega Prime 611*2^3398273+1 found by Randall Scalise of the United States
2017 May 12 - Mega Prime 1049*2^3395647+1 found by Randall Scalise of the United States
2017 May 3 - Mega Prime 555*2^3393389+1 found by Douglas B. McKay of the United States
2017 April 29 - Mega Prime 609*2^3392301+1 found by user "jimmy" of Belgium
2017 April 28 - Mega Prime 805*2^3391818+1 found by Reiner Elgetz of Germany
2017 April 26 - Generalized Fermat Mega Prime 46077492^131072+1 found by Jeffrey Mangio of the United States
2017 April 23 - Mega Prime 663*2^3390469+1 found by Rolf Henrik Nilsson of Sweden
2017 March 22 - Generalized Fermat Mega Prime 2676404^262144+1 found by Wolfgang Schwieger of Germany
2017 March 18 - Generalized Fermat Mega Prime 45570624^131072+1 found by Vince Splain of the United States
2017 March 14 - Mega Prime 621*2^3378148+1 found by Randall Scalise of the United States
2017 March 14 - Mega Prime 1093*2^3378000+1 found by Andreas Rohmann of Germany
2017 March 12 - Mega Prime 861*2^3377601+1 found by Mike Kinney of the United States
2017 March 11 - Generalized Fermat Mega Prime 2611204^262144+1 found by Roman Vogt of Germany
2017 February 24 - Generalized Fermat Mega Prime 2514168^262144+1 found by William de Thomas of Puerto Rico
2017 February 23 - Generalized Fermat Mega Prime 45315256^131072+1 found by William Donovan of the United States
2017 February 21 - Mega Prime 839*2^3369383+1 found by Robert Lacroix of Canada
2017 February 20 - Mega Prime 677*2^3369115+1 found by Wolfgang Schmidt of Germany
2017 February 18 - Mega Prime 715*2^3368210+1 found by Daniel Frużyński of Poland
2017 February 18 - Mega Prime 617*2^3368119+1 found by Kimmo Koski of Finland
2017 February 17 - Mega Prime 777*2^3367372+1 found by Lars Fricke of Germany
2017 February 9 - Mega Prime 533*2^3362857+1 found by Hans-Jürgen Bergelt of Germany
2017 February 9 - Mega Prime 619*2^3362814+1 found by Daniel Frużyński of Poland
2017 February 1 - Generalized Fermat Mega Prime 44919410^131072+1 found by Vince Splain of the United States
2017 January 19 - Mega Prime 1183*2^3353058+1 found by Michele T. Mazzucato of Italy
2017 January 16 - Mega Prime 543*2^3351686+1 found by Simon Rawles of the United Kingdom
2016 December 12 - Mega Prime 733*2^3340464+1 found by Randall Scalise of the United States
2016 December 11 - AP26 142099325379199423+16549135*23#*n for n=0..25 found by Koichi Soraku of Japan
2016 December 11 - Generalized Fermat Mega Prime 44438760^131072+1 found by Håkan Lind of Sweden
2016 December 3 - Mega Prime 651*2^3337101+1 found by Konstantin Stanko of the Czech Republic
2016 November 29 - Mega Prime 849*2^3335669+1 found by Randall Scalise of the United States
2016 November 27 - Mega Prime 611*2^3334875+1 found by John S Chambers of the United States
2016 November 26 - Generalized Fermat Mega Prime 44330870^131072+1 found by Eric Eskam of the United States
2016 November 24 - Generalized Fermat Mega Prime 2042774^262144+1 found by Tsuyoshi Ohsugi of Japan
2016 November 12 - Mega Prime 673*2^3330436+1 found by Randall Scalise of the United States
2016 November 4 - Mega Prime 655*2^3327518+1 found by Paul Mazumdar of the United Kingdom
2016 November 3 - AP26 149836681069944461+7725290*23#*n for n=0..25 found by Takeshi Nakamura of Japan
2016 November 3 - Mega Prime 659*2^3327371+1 found by Dejana Ristic of Germany
2016 November 2 - Mega Prime 821*2^3327003+1 found by Randall Scalise of the United States
2016 October 31 - World Record Sierpinski Problem ("Colbert Number") Mega Prime 10223*2^31172165+1 found by Szabolcs Péter of Hungary
2016 October 30 - Mega Prime 555*2^3325925+1 found by Alexander Falk of the United States
2016 October 24 - Mega Prime 791*2^3323995+1 found by Randall Scalise of the United States
2016 October 21 - Mega Prime 597*2^3322871+1 found by Randall Scalise of the United States
2016 October 14 - Generalized Fermat Mega Prime 44085096^131072+1 found by Alejandro V. Mena of Mexico
2016 October 8 - World Record Generalized Cullen Mega Prime 682156*79^682156+1 found by Franz-Xaver Harvanek of Austria
2016 October 8 - Mega Prime 415*2^3559614+1 found by Randall Scalise of the United States
2016 October 5 - Generalized Fermat Mega Prime 44049878^131072+1 found by Alexander Falk of the United States
2016 September 30 - Mega Prime 465*2^3536871+1 found by Kenneth Biscop of Belgium
2016 September 28 - Mega Prime 447*2^3533656+1 found by Stefan Geiger of Austria
2016 September 14 - World Record Twin Primes 2996863034895*2^1290000 ±1 found by Tom Greer of the United States
2016 September 5 - Mega Prime 495*2^3484656+1 found by Randall Scalise of the United States
2016 August 29 - Mega Prime 491*2^3473837+1 found by Stephen P. Norton of the United States
2016 August 23 - Mega Prime 453*2^3461688+1 found by Randall Scalise of the United States
2016 August 20 - World Record SR5 Base 5 Mega Prime 180062*5^2249192-1 found by Stefan Larsson of Sweden
2016 August 10 - Generalized Fermat Mega Prime 1828858^262144+1 found by Brook Harste of the United States
2016 July 25 - Mega Prime 479*2^3411975+1 found by Matt Jurach of the United States
2016 July 14 - Mega Prime 453*2^3387048+1 found by Andreas Mueller of Germany
2016 June 25 - Mega Prime 403*2^3334410+1 found by Roman Trunov of Russia
2016 June 24 - Mega Prime 309*2^3577339+1 found by Russell Mathers of the United Kingdom
2016 June 23 - Mega Prime 381*2^3563676+1 found by Milan Fňašek of the Czech Republic
2016 June 22 - Mega Prime 351*2^3545752+1 found by Sylvanus A. Zimmerman of the United States
2016 June 22 - Mega Prime 345*2^3532957+1 found by William de Thomas of Puerto Rico
2016 June 21 - Mega Prime 329*2^3518451+1 found by Stefan Larsson of Sweden
2016 June 20 - Mega Prime 323*2^3482789+1 found by Scott Brown of the United States
2016 May 30 - World Record SR5 Base 5 Mega Prime 53546*5^2216664-1 found by Tom Greer of the United States (This is the 100th mega prime discovered at PrimeGrid)
2016 May 16 - Mega Prime 373*2^3404702+1 found by Seonghwan Kim of South Korea
2016 May 9 - Mega Prime 303*2^3391977+1 found by Andreas Mueller of Germany
2016 May 4 - Generalized Fermat Mega Prime 1615588^262144+1 found by Brook Harste of the United States
2016 April 10 - Mega Prime 369*2^3365614+1 found by Will Steinbach of the United States
2016 March 25 - World Record SR5 Base 5 Mega Prime 296024*5^2185270-1 found by Steven Wong of the United Kingdom
2016 March 24 - Mega Prime 393*2^3349525+1 found by Timothy Reichard of the United States
2016 March 15 - World Record SR5 Base 5 Mega Prime 92158*5^2145024+1 found by Karl Burridge of Australia
2016 March 6 - World Record SR5 Base 5 Mega Prime 77072*5^2139921+1 found by Wolfgang Becker of Germany
2016 March 5 - Generalized Fermat Mega Prime 1488256^262144+1 found by Stefan Larsson of Sweden
2016 February 29 - World Record Sophie Germain Prime 2618163402417*2^1290000-1 found by Scott Brown of the United States
2016 February 25 - Generalized Fermat Mega Prime 43165206^131072+1 found by Alen Kecic of Germany
2016 February 24 - Generalized Fermat Mega Prime 43163894^131072+1 found by David E. Miller of the United States
2016 February 24 - Mega Prime 189*2^3596375+1 found by Hiroyuki Okazaki of Japan
2016 February 21 - Mega Prime 387*2^3322763+1 found by Sami Heikkila of Finland
2016 February 16 - Generalized Fermat Mega Prime 1415198^262144+1 found by Frank Matillek of Germany
2016 February 9 - Mega Prime 275*2^3585539+1 found by Tyler Bredl of the United States
2016 January 25 - Mega Prime 251*2^3574535+1 found by Randall Scalise of the United States
2016 January 11 - World Record SR5 Base 5 Mega Prime 306398*5^2112410-1 found by André Ahlfors Dahl of Sweden
2015 November 10 - World Record SR5 Base 5 Mega Prime 154222^2091432+1 found by Scott Brown of the United States
2015 November 9 - Generalized Fermat Mega Prime 42654182^131072+1 found by Andrew M Farrow of Australia
2015 October 30 - Mega Prime 191*2^3548117+1 found by Roman Azarenko of Russia
2015 October 21 - World Record SR5 Base 5 Mega Prime 100186*5^2079747-1 found by Toshitaka Kumagai of Japan
2015 September 1 - Mega Prime 141*2^3529287+1 found by Chgris Hoefliger of Switzerland
2015 August 2 - Mega Prime 135*2^3518338+1 found by Evelyn Chew of Australia
2015 June 23 - World Record 321 Mega Prime 3*2^11895718-1 found by Michael Schulz of Germany
2015 May 23 - World Record SR5 Base 5 Mega Prime 144052*5^2018290+1 found by Wolfgang Schmidt of Germany
2015 May 10 - Mega Prime 195*2^3486379+1 found by Naoki Yoshioka of Japan
2015 May 10 - Mega Prime 249*2^3486411+1 found by Evelyn Chew of Australia
2015 April 19 -- Mega Prime 197*2^3477399+1 found by Tom Greer of the United States
2015 March 13 - World Record 321 Mega Prime 3*2^11731850-1 found by Karsten Klopffleisch of Germany
2015 March 9 - World Record 27121 Mega Prime 27*2^5213635+1 found by Hiroyuki Okazaki of Japan
2015 February 1 - Mega Prime 159*2^3425766+1 found by Evelyn Chew of Australia
2015 January 7 - Mega Prime 245*2^3411973+1 found by Rick Channing of the United States
2015 January 6 - Mega Prime 177*2^3411847+1 found by William Darney of the United States
2015 January 6 - World Record Extended Sierpinski Problem Mega Prime 161041*2^7107964+1 found by Martin Vanc of the Czech Republic
2014 December 1 - Mega Prime 255*2^3395661+1 found by John Christy of the United States
2014 November 22 - World Record 321 Mega Prime 3*2^11484018-1 found by Serhiy Gushchak of Ukraine
2014 October 18 - World Record SR5 Base 5 Mega Prime 109208*5^1816285+1 Found by Scott Brown of the United States
2014 October 4 - World Record Riesel Problem Mega Prime 502573*2^7181987-1 found by Denis Iakovlev of Russia
2014 October 2 - World Record Riesel Problem Mega Prime 402539*2^7173024-1 found by Walter Darimont of Belgium
2014 September 23 - Mega Prime 179*2^3371145+1 found by John Christy of the United States
2014 September 21 - World Record SR5 Base 5 Mega Prime 325918*5^1803339-1 Found by Jörg Meili of Switzerland
2014 August 22 - 27121 Mega Prime 27*2^4583717-1 found by Hans Joachim Böhm of Germany
2014 August 17 - World Record SR5 Base 5 Mega Prime 1337785^1785689+1 Found by Guo Hua Miao of China
2014 July 25 - World Record (and first ever) Mega Prime Fermat Divisor 193*2^3329782+1 Divides F(3329780) found by Raymond Ottusch of the United States
2014 July 24 - Mega Prime 129*2^3328805+1 found by Eric Clifton of the United States
2014 July 23 - World Record SR5 Base 5 Mega Prime 24032*5^1768249+1 Found by Hiroyuki Okazaki of Japan
2014 July 17 - 27121 Mega Prime 27*2^4542344-1 found by Scott Brown of the United States
2014 July 4 - Mega Prime 35*2^3587843+1 found by Peter Tibbott of the United Kingdom
2014 June 27 - World Record SR5 Base 5 Mega Prime 138172*5^1714207-1 found by Walter Dairmont of Belgium
2014 June 19 - World Record SR5 Base 5 Mega Prime 22478*5^1675150-1 found by Guo Hua Miao of China
2014 June 10 - Mega Prime 35*2^3570777+1 found by Robert Lacroix of Canada
2014 June 10 - Mega Prime 33*2^3570132+1 found by Fabrice Le Foulher of France
2014 May 6 - Mega Prime 93*2^3544744+1 found by Michał Gasewicz of Poland
2014 April 25 - World Record SR5 Base 5 Mega Prime 326834*5^1634978-1 found by Scott Brown of the United States
2014 April 9 - World Record SR5 Base 5 Mega Prime 207394*5^1612573-1 found by Honza Cholt of the Czech Republic
2014 April 9 - World Record SR5 Base 5 Mega Prime 104944*5^1610735-1 found by Brian Smith of Germany
2014 March 28 - Mega Prime 51*2^3490971+1 found by Stefan Larsson of Sweden
2014 March 28 - Mega Prime 87*2^3496188+1 found by Gary Craig of the United States
2014 March 21 - World Record SR5 Base 5 Mega Prime 330286*5^1584399-1 found by Scott Brown of the United States
2014 February 6 - World Record SR5 Base 5 Mega Prime 22934*5^1536762-1 found by Keishi Toda of Japan
2014 January 31 - World Record SR5 Base 5 Mega Prime 178658*5^1525224-1 found by Keishi Toda of Japan
2014 January 17 - World Record SR5 Base 5 Mega Prime 59912*5^1500861+1 found by Raymond Ottusch of the United States
2014 January 14 - World Record 321 Mega Prime 3*2^10829346+1 found by Sai Yik Tang of Malaysia
2013 December 29 - World Record SR5 Base 5 Mega Prime 37292*5^1487989+1 found by Stephen R. Cilliers of South Africa
2013 December 25 - World Record Riesel Problem Mega Prime 40597*2^6808509-1 found by Frank Meador of the United States
2013 December 4 - World Record SR5 First Ever Base 5 Mega Prime 173198*5^1457792-1 found by Motohiro Ohno of Japan
2013 October 10 - World Record Riesel Problem Mega Prime 304207*2^6643565-1 found by Randy Ready of the United States
2013 October 5 - World Record Riesel Problem Mega Prime 398023*2^6418059-1 found by Vladimir Volynsky of Russia
2013 August 30 - Second Largest Factorial Prime 147855!-1 found by Pietari Snow of Finland
2013 June 18 - Prime Fermat Divisor 2145*2^1099064+1 Divides F(1099061) found by Sai Yik Tang of Malaysia
2013 May 13 - World Record Prime Fermat Divisor 57*2^2747499+1 Divides F(2747497) found by Marshall Bishop of the United States
2013 March 10 - Prime Fermat Divisor 183*2^1747660+1 Divides F(1747656) found by Bart van Rooijen of the Netherlands
2012 October 23 - Proth Mega Prime 9*2^3497442+1 found by Heinz Ming of Switzerland
2012 November 2 - Proth Mega Prime 7*2^5775996+1 found by Martyn Elvy of New Zealand
2012 August 8 - World Record Generalized Fermat Mega Prime 475856^524288+1 found by Masashi Kumagai of Japan
2012 June 20 - World Record Generalized Fermat Mega Prime 356926^524288+1 found by user bherbihyewrbg of Japan
2012 June 15 - World Record Generalized Fermat Mega Prime 341112^524288+1 found by Peyton Hayslette of the United States
2012 June 23 - World Record Riesel Problem Mega Prime 252191*2^5497878-1 found by Jan Haller of Germany
2012 June 13 - Fermat Number divisor 1705*2^906110+1 Divides F(906108) found by Robert Boniecki of the United States
2012 May 2 - Fermat Number divisor 7905*2^352281 +1 Divides F(352279) found by James Boerner of the United States
2012 April 19 - Generalized Fermat Mega Prime 773620^262144+1 found by Senji Yamashita of Japan
2012 April 9 - World Record Sophie Germain Prime 18543637900515*2^666667-1 found by Philipp Bliedung of the United States
2012 February 28 - World Record Primorial Prime 1098133#-1 found by James P. Burt of the Cayman Islands
2012 February 28 - 27 Mega Prime 27*2^3855094-1 found by Pietari Snow of Finland
2012 February 25 - 121 Mega Prime 121*2^4553899-1 found by Timothy D. Winslow of the United States
2012 February 25 - World Record Twin Primes [1] found by Timothy D. Winslow of the United States
2012 February 12 - Generalized Fermat Mega Prime 676754^262144+1 found by Carlos Loureiro of Portugal
2012 February 7 - Fermat Number divisor 131*2^1494099 +1 Divides F(1494096) found by Rob Derrera of the United States
2012 February 2 - Riesel Problem Prime 162941*2^993718-1 found by Dmitry Domanov of Russia
2012 January 29 - World Record Generalized Cullen Prime 427194*113^427194+1 found by Ricky L. Hubbard of the United States
2012 January 18 - Generalized Fermat Mega Prime 525094^262144+1 found by David Tomecko of the United States
2012 January 17 - Generalized Fermat Mega Prime 81*2^3352924+1 found by Michal Gasewicz of Poland
2012 January 4 - Fermat Number divisor 329*2^1246017+1 Divides F(1246013) found by Bruce Dodson of the United States
2011 December 25 - Twin Primes 3756801695685*2^666669±1 found by STimothy D. Winslow of the United States
2011 November 19 - Generalized Fermat Mega Prime 75898^524288+1 found by Michael Goetz of the United States
2011 October 29 - Generalized Fermat Mega Prime 361658^262144+1 found by Michel Johnson of Germany
2011 September 09 - Fermat Number divisor 25*2^2141884+1 Divides F(2141872) found by Grzegorz Granowski of Poland
2011 July 08 - Fermat Number divisor 4479*2^226618+1 Divides F(226614) found by Peter Doggart of the United Kingdom
2011 July 01 - Fermat Number divisor 3771*2^221676+1 Divides F(221670) found by Mark Doom of the United States
2011 June 22 - Fermat Number divisor 9*2^2543551+1 Divides F(2543548) found by Scott Brown of the United States
2011 June 11 - Factorial Prime 110059!+1 found by Peter Doggart of the United Kingdom
2011 May 31 - Riesel Problem Mega Prime 353159*2^4331116-1 found by Jaakko Reinman of Finland
2011 May 26 - Riesel Problem Mega Prime 141941*2^4299438-1 found by Scott Brown of the United States
2011 May 8 - Riesel Problem Mega Prime 415267*2^3771929-1 found by Alexey Tarasov of Ukraine
2011 May 8 - Riesel Problem Mega Prime 123547*2^3804809-1 found by Jakub Łuszczek of Poland
2011 April 5 - Riesel Problem Mega Prime 65531*23629342-1 found by Adrian Schori of Switzerland
2011 March 12 - Fermat Number divisor 7333*2^138560+1 Divides F(138557) found by Dirk D'huyvetters of Belgium
2011 March 08 - Generalized Fermat Mega Prime 40734^262144+1 found by Senji Yamashita of Japan
2011 February 24 - Generalized Woodall Prime 404882*43^404882-1 found by Ricky L. Hubbard of the United States
2011 February 21 - 321 Mega Prime 3*2^7033641+1 found by Michael Herder
2011 February 08 - Generalized Fermat Mega Prime 145310^262144+1 found by Ricky L Hubbard of the United States
2011 January 14 - Riesel Problem Mega Prime 428639*2^3506452-1 found by Brett Melvold of Australia
2010 December 20 - Primorial Prime 843301#-1 found by Michał Gasewicz of Poland
2010 December 14 - Factorial Prime 103040!-1 found by James Winskill of New Zealand
2010 November 21 - Riesel Problem Mega Prime 191249*2^3417696-1 found by Jonathan Pritchard of the United Kingdom
2010 October 04 - Factorial Prime 94550!-1 found by Dmitry Domanov of Russia
2010 April 24 - 321 Mega Prime 3*2^6090515-1 found by David Mumper of the United States
2010 April 12 - AP26 43142746595714191+23681770*23#*n for n=0..25 found by Benoãt Perichon of France
2009 December 07 - Generalized Woodall Prime 563528*13^563528-1 found by Lennart Vogel of Sweden
2009 July 25 - Twin Primes 65516468355*2^333333±1 found by SunGard Availability Services of the United States
2009 July 25 - Cullen Mega Prime 6679881*2^6679881+1 found by Anonymous of Japan
2009 April 20 - Cullen Mega Prime 6328548*2^6328548+1 found by Dennis R. Gesker of the United States
2009 April 03 - 321 Mega Prime 3*2^5082306+1 found by Andy Brady of the United States
2009 March 31 - Fermat Number divisor 659*2^617815+1 Divides F(617813) found by Eric Embling of the United States
2009 March 06 - Fermat Number divisor 519*2^567235+1 Divides F(567233) found by Senji Yamashita of Japan
2008 December 27 - Fermat Number divisor 651*2^476632+1 Divides F(476624) found by Eric Ueda of the United States
2008 March 23 - 321 Mega Prime 3*2^4235414-1 found by Dylan Bennett of Canada
2007 December 21 - Woodall Mega Prime 3752948*2^3752948-1 found by Matthew J. Thompson of the United States
2007 August 13 - Woodall Prime 2367906*2^2367906-1 found by Stephen Kohlman of Canada
2007 August 04 - Woodall Prime 2013992*2^2013992-1 found by Lasse Mejling Andersen of Denmark

Significant Discoveries

What is a "Significant Prime"?

List of Significant Primes

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