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Mersenne Prime Number discovery - 242643801-1 is Prime!

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GIMPS Discovers 47th Mersenne Prime,

242,643,801-1 is newest, but not the largest, known Mersenne Prime.

ORLANDO, Florida, April 12, 2009 — The 47th known Mersenne prime, 242,643,801-1, a 12,837,064 digit number was found by Odd Magnar Strindmo from Melhus, Norway! This prime is the second largest known prime number, a "mere" 141,125 digits smaller than the Mersenne prime found last August.

Odd is an IT professional whose computers have been working with GIMPS since 1996 testing over 1400 candidates. This calculation took 29 days on a 3.0 GHz Intel Core2 processor.

The prime was first verified on June 12th by Tony Reix of Bull SAS in Grenoble, France using the Glucas program running on Bull NovaScale HPC servers, one featuring Itanium2 CPUs and another featuring Nehalem CPUs. The prime was later independently verified by Rob Giltrap of Sun Microsystems using Ernst Mayer's Mlucas program running on a Sun SPARC Enterprise M9000 Server.

Perfectly Scientific, Dr. Crandall's company which developed the FFT algorithm used by GIMPS, makes souvenir posters you can order. You'll need a good magnifying glass to read all 12.8 million digits!