PrimeGrid’s
27121 Prime Search
On 22 August 2014, 4:33:59, PrimeGrid’s 27121 Prime Search, through
PRPNet and in collaboration with the 12121 Search (k=27 sister project), has
found the mega prime:
27*24583717-1
The prime is 1,379,838 digits long and will enter Chris Caldwell's “The Largest
Known Primes Database” (http://primes.utm.edu/primes) ranked 48th overall.
The discovery was made by Hans Joachim Böhm of Germany using an Intel(R)Core(TM)2 Quad CPU Q9550 @ 2.83GHz Processor with 4GB RAM, running
Microsoft Windows 7 Ultimate. This computer took about 15 hours 24 minutes
to complete the primality test using LLR. Hans is a member of theSETI.Germany Team.
The prime was verified internally.
Credits for the discovery are as follows:
1.
2.
3.
4.
5.

Hans Joachim Böhm (Germany), discoverer
PrimeGrid, et al.
Srsieve, sieving program developed by Geoff Reynolds
PSieve, sieving program developed by Ken Brazier and Geoff Reynolds
LLR, primality program developed by Jean Penné

Entry in “The Largest Know Primes Database” can be found here:
http://primes.utm.edu/primes/page.php?id=118388
PrimGrid’s 27121 Prime Search is a collaboration with the 12121 Search, which
was established on 5/24/2004 to search for large primes of the form 121*2^n-1.
Later, on 3/1/2005, they added k=27 to their search. Their "short term" goal is tosearch for n up to 10M. PrimeGrid added the +1 form and searches both k’sand forms together.
Using a single PC would have taken years to find this prime. So this timely
discovery would not have been possible without the thousands of volunteers
who contributed their spare CPU cycles. A special thanks to everyone whocontributed their advice and/or computing power to the search - especially all
the sievers who work behind the scenes to make a find like this possible.
The 27121 Prime Search will continue to seek even larger primes. To join thesearch please visit PrimeGrid: http://www.primegrid.com

PrimeGrid’s
27121 Prime Search
About PrimeGrid
PrimeGrid is a distributed computing project, developed by Rytis Slatkevičius,Lennart Vogel, and John Blazek, which utilizes BOINC and PRPNet to searchfor primes. PrimeGrid's primary goal is to bring the excitement of prime finding
to the "everyday" computer user. Simply download the software and let yourcomputer do the rest. Participants can choose from a variety of prime forms tosearch. With a little patience, you may find a large or even record breaking
prime.
BOINC
The Berkeley Open Infrastructure for Network Computing (BOINC) is asoftware platform for distributed computing using volunteered computerresources. It allows users to participate in multiple distributed computing
projects through a single program. Currently BOINC is being developed bya team based at the University of California, Berkeley led by DavidAnderson.
This platform currently supports projects from biology to math toastronomy. For more information, please visit BOINC:
http://boinc.berkeley.edu
PRPNetPRPNet is a client/server application written by Mark Rodenkirch that is
specifically designed to help find prime numbers of various forms. It iseasily ported between various OS/hardware combinations. PRPNet does
not run each PRP test itself, but relies on helper programs, such as LLR,
PFGW, phrot, wwww, and genefer to do the work.
For more information, please visit PrimeGrid’s PRPNet forum thread:
http://www.primegrid.com/forum_thread.php?id=1215
For more information about PrimeGrid and a complete list of available prime
search projects, please visit: http://www.primegrid.com