About
PrimeGrid's primary goal is to advance mathematics by enabling everyday computer users to contribute their system's processing power towards prime finding. By simply
downloading and installing BOINC and attaching to the PrimeGrid project,
participants can choose from a variety of prime forms to search. With a little patience, you may find a large or even record
breaking prime and enter into Chris Caldwell's The Largest Known Primes Database as
a Titan!
PrimeGrid's secondary goal is to provide relevant educational materials about primes. Additionally, we wish to contribute to the
field of mathematics.
Lastly, primes play a central role in the cryptographic systems which are used for computer security. Through the study of prime
numbers it can be shown how much processing is required to crack an encryption code and thus to determine whether current
security schemes are sufficiently secure. PrimeGrid is currently running several sub-projects:
- 321 Prime Search: searching for
mega primes of the form 3·2n±1.
- Cullen-Woodall Search: searching for
mega primes of forms n·2n+1 and
n·2n−1.
- Extended Sierpinski Problem: helping solve the Extended Sierpinski Problem.
- Generalized Fermat Prime Search: searching for
megaprimes of the form b2n+1.
- Prime Sierpinski Project: helping Prime Sierpinski Project solve the Prime Sierpinski Problem.
- Proth Prime Search: searching for primes of the form k·2n+1.
- Seventeen or Bust: helping to solve the Sierpinski Problem.
- Sierpinski/Riesel Base 5: helping to solve the Sierpinski/Riesel Base 5 Problem.
- Sophie Germain Prime Search: searching for primes p and 2p+1.
- The Riesel problem: helping to solve the Riesel Problem.
Recent Significant Primes
On 24 December 2019, 08:20:15 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
3214654524288+1
The prime is 3,411,613 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 3 rd for Generalized Fermat primes and 30 th overall.
The discovery was made by Alen Kecic ( Freezing) of Germany
using an NVIDIA GeForce GTX 1660 Ti in an Intel(R) Core(TM) i7-7820X CPU @ 3.60GHz with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition.
This computer took about 51 minutes to probable prime (PRP) test with GeneferOCL3.
Alen is a member of the SETI.Germany team.
The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 32GB RAM, running Windows 10 Professional x64 Edition.
This computer took about 1 day, 1 hour and 45 minutes to complete the primality test using multithreaded LLR.
For more information, please see the Official Announcement.
On 24 December 2019, 01:28:13 UTC, PrimeGrid's Extended Sierpinski Problem found the Mega prime:
99739·214019102+1
The prime is 4,220,176 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 20 th overall.
This find eliminates k=99739; 9 k's remain in the Extended Sierpinski Problem.
The discovery was made by Brian D. Niegocki ( Penguin) of the United States
using an Intel(R) Xeon(R) Gold 6140 CPU @ 2.30GHz with 1GB RAM, running Linux Ubuntu.
This computer took about 14 hours and 14 minutes to complete the primality test using multithreaded LLR.
Brian is a member of the Antarctic Crunchers team.
For more information, please see the Official Announcement.
On 5 December 2019, 08:39:29 UTC, PrimeGrid's Generalized Fermat Prime Search found the Generalized Fermat mega prime:
9125820262144+1
The prime is 1,824,594 digits long and enters Chris Caldwell's The Largest Known Primes Database
ranked 14 th for Generalized Fermat primes and 82 nd overall.
The discovery was made by Yoshimitsu Kato ( yoshi) of Japan
using an NVIDIA GeForce GTX 1660 Ti in an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10.
This computer took about 22 minutes to probable prime (PRP) test with Genefer OCL2.
Yoshimitsu Kato is a member of Team JPN.
The PRP was confirmed prime by an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional x64 Edition.
This computer took about 16 hours, 30 minutes to complete the primality test using multithreaded LLR.
For more information, please see the Official Announcement.
Other significant primes
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News 
International Day of Education Challenge
To celebrate UNESCO's International Day of Education, PrimeGrid is having a 1-day challenge on January 24th 2020, 00:00:00 UTC to 23:59:59 UTC.
Tasks from the 321-Sieve project which are downloaded and completed during the challenge will count towards your challenge score.
For more information and discussion, please see the official challenge thread: https://www.primegrid.com/forum_thread.php?id=8971
Best of luck!
20 Jan 2020 | 21:59:52 UTC
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GFN-524288 Mega Prime!
On 24 December 2019, 08:20:15 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime:
3214654^524288+1
The prime is 3,411,613 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 3rd for Generalized Fermat primes and 30th overall.
The discovery was made by Alen Kecic (Freezing)of Germany using a GeForce GTX 1660 Ti in an Intel(R) Core(TM) i7-7820X CPU @ 3.60GHz with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition. This GPU took about 51 minutes to complete the probable prime (PRP) test using GeneferOCL5. Alen is a member of the SETI.Germany Team.
The PRP was verified on 24 December 2019, 10:12:18 UTC by John Holmes (John J. Holmes) of the United States using a GeForce GTX 970 in an Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz with 16GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 2 hours, 4 minutes to complete the probable prime (PRP) test using GeneferOCL3.
The PRP was confirmed prime by an Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 1 day, 1 hour, 45 minutes to complete the primality test using multithreaded LLR.
For more details, please see the official announcement.
13 Jan 2020 | 16:29:44 UTC
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ESP Mega Prime!
On 24 December 2019, 01:28:13 UTC, PrimeGrid's Extended Sierpinski Problem found the Mega Prime:
99739*2^14019102+1
The prime is 4,220,176 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 20th overall. This find eliminates k=99739; 9 k's remain in the Extended Sierpinski Problem.
The discovery was made by Brian D. Niegocki (Penguin) of the United States using an Intel(R) Xeon(R) Gold 6140 CPU @ 2.30GHz with 1GB RAM, running Linux Ubuntu. This computer took about 14 hours, 14 minutes to complete the primality test using LLR. Brian is a member of the Antarctic Crunchers team.
The prime was verified on 24 December 2019, 04:37:31 UTC by Pavel Atnashev (Pavel Atnashev) of Russia using an Intel(R) Xeon(R) E5-2680 v2 @ 2.80GHz with 8GB RAM, running Linux. This computer took about 4 hours, 6 minutes to complete the primality test using LLR. Pavel is a member of the Ural Federal University team.
For more details, please see the official announcement.
13 Jan 2020 | 12:50:37 UTC
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And Another GFN-262144 Find!!
On 5 December 2019, 08:39:29 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime:
9125820^262144+1
The prime is 1,824,594 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 14th for Generalized Fermat primes and 82nd overall.
The discovery was made by Yoshimitsu Kato (yoshi) of Japan using a GeForce GTX 1660 Ti in an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10. This GPU took about 22 minutes to complete the probable prime (PRP) test using Genefer OCL2. Yoshimitsu Kato is a member of Team JPN.
The prime was verified on 5 December 2019, 08:41:59 UTC by Igor Keller (IKI) of France using a GeForce GTX 1080 in an Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz with 16GB RAM, running Microsoft Windows 8.1. This GPU took about 26 minutes to complete the probable prime (PRP) test using Genefer OCL2. Igor Keller is a member of the Gridcoin team.
The PRP was confirmed prime by an Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 16 hours, 30 minutes to complete the primality test using multithreaded LLR.
For more details, please see the official announcement.
24 Dec 2019 | 16:36:57 UTC
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GFN-262144 Find!
On 6 November 2019, 11:59:08 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime:
8883864^262144+1
The prime is 1,821,535 digits long and enters Chris Caldwell's The Largest Known Primes Database ranked 14th for Generalized Fermat primes and 80th overall.
The discovery was made by Rod Skinner (rjs5) of the United States using a GeForce RTX 2080 Ti in an Intel(R) Core(TM) i9-9980XE CPU @ 3.00GHz with 63GB RAM, running Linux Fedora. This GPU took about 8 minutes to complete the probable prime (PRP) test using Genefer OCL2. Rod Skinner is a member of Intel Corporation team.
The prime was verified on 6 November 2019, 14:33:32 UTC by Tom Greer (tng*) of the United States using a GeForce RTX 2070 SUPER in an Intel(R) Core(TM) i9-9900X CPU @ 3.50GHz with 32GB RAM, running Microsoft Windows 10. This GPU took about 13 minutes to complete the probable prime (PRP) test using Genefer OCL2. Tom Greer is a member of the Sicituradastra. team.
The PRP was confirmed prime by an Intel(R) Xeon(R) E3-1240 v6 CPU @ 3.70GHz with 32 GB RAM, running Debian Linux. This computer took about 17 hours 30 minutes to complete the primality test using LLR.
For more details, please see the official announcement.
24 Dec 2019 | 16:21:30 UTC
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Newly reported primes(Mega-primes are in bold.)
155253548^32768+1 (k4m1k4z3); 4870727627265*2^1290000-1 (jhwells); 4872489023685*2^1290000-1 (Daniel); 155179392^32768+1 (Johny); 4870133466627*2^1290000-1 (zombie67 [MM]); 66982940^131072+1 (288larsson); 155048428^32768+1 (ReallyGrid); 4869186899757*2^1290000-1 (Frank [RKN]); 4867595955087*2^1290000-1 (Nita); 154949962^32768+1 (SkyHighWeFly); 4868356531887*2^1290000-1 (Sean); 4867271957247*2^1290000-1 (Honza); 154858360^32768+1 (SkyHighWeFly); 9793*2^1554294+1 (Darryl); 2493*2^1554324+1 (recursive); 154819908^32768+1 (SEARCHER); 154795838^32768+1 (hase); 4863978613965*2^1290000-1 (Eikelenboom); 154758186^32768+1 (Johny); 66901180^131072+1 ((Ryle)) Top Crunchers:Top participants by RAC | Top teams by RAC |
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