The 43rd Mersenne prime number has just been found by comps
running 9 years at Central Missouri State University.
It is: *drum roll*
(2^30402457) - 1.
Its 9,152,052 digits surpassing the last one which had a mere
7 million decimal digits.
It seems there is a prize of 100,000 $US for the first prime with
more than 10 million digits and it just missed. Oh well, another
nine years and they will have that 100K nailed.

Originally posted by sonhouse The 43rd Mersenne prime number has just been found by comps
running 9 years at Central Missouri State University.
It is: *drum roll*
(2^30402457) - 1.
Its 9,152,052 digits surpassing the last one which had a mere
7 million decimal digits.
It seems there is a prize of 100,000 $US for the first prime with
more than 10 million digits and it just missed. Oh well, another
nine years and they will have that 100K nailed.

The 42nd Mersenne prime was found in February 2005. This one was found in December 2005. Also the computers on campus are a part of PrimeNet a disributed computer network. The central server hands out numbers to check (all of the form 2^p -1) and your computer returns the positive or negative result to the main computer. Checking large numbers for primality is a long process, the computer that found this prime took 50 days of idle processes to do so.

Also if you found a 10 million digit mersenne prime using PrimeNet you would not get $100k you would get $50k (http://www.mersenne.org/prize.htm).