An amateur scientist has discovered the largest known prime number, calculated by multiplying 77,232,917 twos, and then subtracting one. On December 26 last year, Jonathan Pace – a 51-year old electrical engineer in the US – stumbled on to the largest known prime number, having 23,249,425 digits. The new prime number, also known as M77232917, is nearly one million digits larger than the previous record prime number, in a special class of extremely rare prime numbers known as Mersenne primes. Mersenne prime is a prime number that is one less than a power of two. They were named for the French monk Marin Mersenne, who studied these numbers more than 350 years ago. The primality proof for the new prime number took six days of non-stop computing. To prove there were no errors in the prime discovery process, the new prime was independently verified using four different programmes on four different hardware configurations.
M77232917 is the 50th known Mersenne prime ever discovered, and are each increasingly difficult to find.Thousands of volunteers use a free software called the Great Internet Mersenne Prime Search (GIMPS) to hunt for new prime numbers. A cash award of $3,000 or 50,000 is offered to anyone lucky enough to find a new prime. Pace has been hunting for big primes with GIMPS for over 14 years. His discovery is eligible for a $3,000 award. GIMPS’ next major goal is to win the $150,000 award administered by the Electronic Frontier Foundation offered for finding a 100 million digit prime number. Credit for this prime goes not only to Pace, but also the thousands of GIMPS volunteers that sifted through millions of non-prime candidates, GIMPS said in a statement.