LOCUS Blog The largest known prime numbers
The largest known prime is the largest integer that is currently known to be a prime number.
It was proven by Euclid that there are infinitely many prime numbers; thus, there is always a prime greater than the largest known prime. Many mathematicians and hobbyists enjoy searching for large prime numbers. This may also be profitable as there are several prizes offered by the Electronic Frontier Foundation for record primes.
The use of electronic computers has accelerated the discoveries and found all records since 1951. The record passed one million digits in 1999, earning a $50,000 prize.
As of March 2008, the largest known prime was discovered by the distributed computing project Great Internet Mersenne Prime Search (GIMPS):
Its predecessor as largest known prime, 230,402,457 − 1, was first shown to be prime on December 15, 2005 by GIMPS also. GIMPS found the 10 latest records on ordinary computers operated by participants around the world.
There is a $100,000 prize for the first known prime with at least 10,000,000 digits. A Mersenne prime 2p − 1 with p ≥ 33,219,281 would have at least 10,000,000 digits, and GIMPS is testing many candidates of this size.
Source: Wikipedia