PrimeGrid

On 18 September 2021, 06:50:25 UTC, PrimeGrid’s Primorial Prime Search, through PRPNet found the mega prime: 3267113#-1 The prime is 1,418,398 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 1st for Primorial primes and 286th overall. The discovery was made by James Winskill (Aeneas) of New Zealand using an Intel(R) Xeon(R) W-2125 CPU @ 4.00GHz with 64GB RAM running Windows 10. This computer took 20 hours 32 minutes to complete the prp test using pfgw64. James Winskill is a member of the PrimeSearchTeam. The prp was verified on 26 September 2021, 01:56:46 UTC by an Intel i7-7700K @ 4.2 GHz with 16 GB RAM, running Gentoo/Linux. This computer took a little over 5 days 8 hours 38 minutes to verify primality of the prp using pfgw64. For more details, please see the official announcement.

The ninth and final challenge of the 2021 Series will be a 10-day challenge marking the yearly Geminids Meteor Shower. The challenge will be offered on the GFN-21, GFN-22, and GFN-DYFL subprojects, beginning 7 December 07:00 UTC and ending 17 December 07:00 UTC. To participate in the Challenge, please select only the GFN-21 and/or GFN-22 and/or GFN-DYFL subprojects in your PrimeGrid preferences section. For more info and discussion, check out the forum thread for this challenge: https://www.primegrid.com/forum_thread.php?id=9804&nowrap=true#152440

On 8 October 2021, 01:38:53 UTC, PrimeGrid’s Sierpinski/Riesel Base 5 Problem project eliminated k=102818 by finding the mega prime: 102818*5^3440382-1 The prime is 2,404,729 digits long and enters Chris Caldwell's “The Largest Known Primes Database” ranked 96th overall. 61 k’s now remain in the Riesel Base 5 problem. The discovery was made by Wes Hewitt (emoga) of Canada using an AMD Ryzen 9 5950X 16-Core Processor with 32GB RAM, running Microsoft Windows 10 Professional x64 Edition. This computer took about 1 hour, 29 minutes to complete the primality test using LLR2. Wes Hewitt is a member of TeAm AnandTech team. The prime was verified on 10 October 2021, 20:14 UTC, by an Intel(R) Core(TM) i7-9800X CPU @ 3.80GHz with 32GB of RAM, running CentOS. This computer took 20 hours and 39 minutes to complete the primality test using LLR2. For more details, please see the official announcement.