On 13 May 2013 12:41:57 UTC, PrimeGrid's Proth Prime Search project found a world record prime Fermat divisor:
57*2^2747499+1 Divides F(2747497)
The prime is 827,082 digits long and will enter Chris Caldwell's The Largest Known Primes Database ranked 1st for prime Fermat divisors and 101st overall. Incidentally, it is also a new record for "weighted" prime Fermat divisors.
The discovery was made by Marshall Bishop (Wintermute) of the United States using an AMD Quad-Core AMD Opteron(tm) Processor 2374 HE with 32 GB RAM running Linux. This computer took about 2 hours 28 minutes to complete the primality test using LLR.
The prime was verified by [AF>Le_Pommier>MacGeneration.com] Sloughi of France using an Intel(R) Xeon(R) CPU E5645 @ 2.40GHz with 12 GB RAM running Mac OS X. This computer took about 4 hour and 46 minutes to complete the primality test using LLR. [AF>Le_Pommier>MacGeneration.com]Sloughi is a member of the L'Alliance Francophone team.
For more details, please see the official announcement.