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 with a multi-million digit prime!
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.
- Generalized Cullen-Woodall Search: searching for mega primes of forms n·bn+1 and
n·bn−1 where n + 2 > b.
- 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 the 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.
- The Riesel problem: helping to solve the Riesel Problem.
- AP27 Search: searching for record length arithmetic progressions of primes.
Recent Significant Primes
On 5 October 2024, 19:55:34 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime
11937916524288+1
The prime is 3,710,349 digits long and will enter The Largest Known Primes Database ranked 13th for Generalized Fermat primes and 88th overall.
The discovery was made by Murray Sondergard ( Sondergard) of Canada using an NVIDIA GeForce GTX 1080 Ti in an Intel(R) Core(TM) i7-5960X CPU @ 3.00GHz with 16GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 1 hour, 21 minutes to complete the probable prime (PRP) test using Genefer22. Murray Sondergard is a member of the Canada team.
The PRP was confirmed prime on 7 October 2024 by an AMD Ryzen 9 7950X3D @ 4.2GHz with 128GB RAM, running Debian 12.5. This computer took about 14 hours, 18 minutes to complete the primality test using LLR.
For more information, please see the Official Announcement.
On 12 August 2024, 06:10:14 UTC, PrimeGrid's Primorial Prime Search found the Mega Prime
6369619#+1
The prime is 2,765,105 digits long and will enter The Largest Known Primes Database ranked 1st for Primorial primes and 155th overall.
The discovery was made by Nick Merrylees ( Nick) of Australia using an Intel(R) Core(TM) i9-9960X @ 3.10GHz with 64GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 5 hours, 55 minutes to complete the probable prime (PRP) test using PRST. Nick Merrylees is a member of BOINC@AUSTRALIA.
The PRP was confirmed prime on 15 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 3 days, 44 minutes to complete the primality test using PFGW.
For more information, please see the Official Announcement.
On 12 August 2024, 01:42:48 UTC, PrimeGrid's Primorial Prime Search found the Mega Prime
6354977#-1
The prime is 2,758,832 digits long and will enter The Largest Known Primes Database ranked 2nd for Primorial primes and 157th overall.
The discovery was made by Tom Greer ( tng) of the United States using an AMD Ryzen 9 9950X @ 4.30GHz with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 4 hours, 24 minutes to complete the probable prime (PRP) test using PRST. Tom Greer is a member of the Antartic Crunchers team.
The PRP was confirmed prime on 17 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 5 days, 6 hours, 49 minutes to complete the primality test using PFGW.
For more information, please see the Official Announcement.
On 6 August 2024, 17:14:36 UTC, PrimeGrid's Primorial Prime Search found the Mega Prime
5256037#+1
The prime is 2,281,955 digits long and will enter The Largest Known Primes Database ranked 1st for Primorial primes and 210th overall.
The discovery was made by Itsuki Kadowaki ( Su_Root@jisaku) of Japan using an AMD Ryzen 9 7950X3D @ 4.20GHz with 64GB RAM, running Microsoft Windows 11 Professional x64 Edition. This computer took about 2 hours, 47 minutes to complete the probable prime (PRP) test using PRST. Itsuki Kadowaki is a member of Team 2ch.
The PRP was confirmed prime on 9 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 3 days, 13 minutes to complete the primality test using PFGW.
For more information, please see the Official Announcement.
On 31 July 2024, 21:55:41 UTC, PrimeGrid's Primorial Prime Search found the Mega Prime
4778027#-1
The prime is 2,073,926 digits long and will enter The Largest Known Primes Database ranked 1st for Primorial primes and 257th overall.
The discovery was made by Kai Presler ( Aperture_Science_Innovators) of Antarctica using an AMD EPYC 7662 64-Core Processor @ 2.0GHz with 64GB RAM, running Linux Mint 21.1. This computer took about 4 hours, 34 minutes to complete the probable prime (PRP) test using PRST. Kai Presler is a member of the [H]ard|OCP team.
The PRP was confirmed prime on 6 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 5 days, 9 hours, 22 minutes to complete the primality test using PFGW.
For more information, please see the Official Announcement.
Other significant primes
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News 
About PPSE and TdP
What you all collectively do during the next 35 days will determine whether PPSE is included in the 2025 edition of Tour de Primes.
If you want to help PPSE to be included in this year's Tour de Primes (TdP), please run PPSE and do NOT run GFN-17. PPSE is about 10 thousand digits below what is necessary to currently be eligible for T5K, and thus for TdP. It's possible to make up the difference in the time remaining before TdP starts (February 1st), but there are currently too may new primes being added to T5K, and each new prime raises the threshold. Primarily, these primes are GFN-17. Your choice is simple: run PPSE and you're more likely to have an easy project with which to earn a TdP badge in February. Run GFN-17, and you'll probably need to find a megaprime to earn a TdP badge.
Everyone is, of course, free to run whatever projects they want to run. It helps, however, to have the information necessary to make an informed decision.
WE DID IT!
PPSE is now officially in T5K.
In order to give the server a little bit of rest, please stop running PPSE until TdP starts.
28 Dec 2024 | 18:07:53 UTC
· Comment
GFN 19 Found!
On 5 October 2024, 19:55:34 UTC, PrimeGrid's Generalized Fermat Prime Search found the Mega Prime:
11937916^524288+1
The prime is 3,710,349 digits long and will enter “The Largest Known Primes Database†ranked 13th for Generalized Fermat primes and 88th overall.
The discovery was made by Murray Sondergard (Sondergard) of Canada using an NVIDIA GeForce GTX 1080 Ti in an Intel(R) Core(TM) i7-5960X @ 3.00GHz with 16GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 1 hour, 21 minutes to complete the probable prime (PRP) test using Genefer22. Murray Sondergard is a member of the Canada team.
The PRP was confirmed prime on 7 October 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 14 hours, 18 minutes to complete the primality test using LLR.
For more details, please see the official announcement.
31 Oct 2024 | 3:40:34 UTC
· Comment
Yet Another PRS Found!
On 12 August 2024, 06:10:14 UTC, PrimeGrid's Primorial Prime Search found the Primorial Prime:
6369619#+1
The prime is 2,765,105 digits long and will enter “The Largest Known Primes Database†ranked 1st for Primorial primes and 155th overall.
The discovery was made by Nick Merrylees (Nick) of Australia using an Intel(R) Core(TM) i9-9960X @ 3.10GHz with 64GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 5 hours, 55 minutes to complete the probable prime (PRP) test using PRST with 5 threads. Nick Merrylees is a member of BOINC@AUSTRALIA.
The PRP was confirmed prime on 15 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 3 days, 44 minutes to complete the primality test using PFGW with 4 threads.
For more details, please see the official announcement.
31 Oct 2024 | 3:23:36 UTC
· Comment
Another PRS Found!
On 12 August 2024, 01:42:48 UTC, PrimeGrid's Primorial Prime Search found the Primorial Prime:
6354977#-1
The prime is 2,758,832 digits long and will enter “The Largest Known Primes Database†ranked 2nd for Primorial primes and 157th overall.
The discovery was made by Tom Greer (tng) of the United States using an AMD Ryzen 9 9950X @ 4.30GHz with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 4 hours, 24 minutes to complete the probable prime (PRP) test using PRST with 4 threads. Tom Greer is a member of Antarctic Crunchers.
The PRP was confirmed prime on 17 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 5 days, 6 hours, 49 minutes to complete the primality test using PFGW with 4 threads.
For more details, please see the official announcement.
31 Oct 2024 | 3:20:13 UTC
· Comment
Another PRS Found!
On 6 August 2024, 17:14:36 UTC, PrimeGrid's Primorial Prime Search found the Primorial Prime:
5256037#+1
The prime is 2,281,955 digits long and will enter “The Largest Known Primes Database†ranked 1st for Primorial primes and 210th overall.
The discovery was made by Itsuki Kadowaki (Su_Root@jisaku) of Japan using an AMD Ryzen 9 7950X3D @ 4.20GHz with 64GB RAM, running Microsoft Windows 11 Professional x64 Edition. This computer took about 2 hours, 47 minutes to complete the probable prime (PRP) test using PRST with 4 threads. Itsuki Kadowaki is a member of Team 2ch.
The PRP was confirmed prime on 9 August 2024 by an AMD Ryzen 9 7950X3D @ 4.20GHz with 128GB RAM, running Debian 12.5. This computer took about 3 days, 13 minutes to complete the primality test using PFGW with 4 threads.
For more details, please see the official announcement.
31 Oct 2024 | 3:04:17 UTC
· Comment
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Newly reported primes(Mega-primes are in bold.)
4895*2^2248593+1 ([TA]Skillz); 5461*2^2248308+1 ([TA]Skillz); 448126420^65536+1 (RobertCoplin); 448387416^65536+1 (owensse); 448411210^65536+1 (Aperture_Science_Innovators); 448263082^65536+1 (Aperture_Science_Innovators); 165*2^6213489+1 (valterc); 448115370^65536+1 (Aperture_Science_Innovators); 4659*2^2247999+1 (T-ryoX); 3551*2^2247531+1 (Gerry Michaud); 4103*2^2246549+1 (Nova); 447853358^65536+1 (ServicEnginIC); 13520762^524288+1 (Boundary_layer); 447271406^65536+1 (RobertCoplin); 1807*2^2247250+1 (meso@Mayoineko); 6573*2^2247101+1 (waffleironhead); 2593*2^2247086+1 (Ryan Propper); 2655*2^2246901+1 (warddr); 1967*2^2246343+1 (GXsimon); 5027*2^2245147+1 (Icecold) Top Crunchers:Top participants by RAC | Top teams by RAC |
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