Largest Prime Number Discovered

On the very early days of new year, the Great Internet Mersenne Prime Search (GIMPS) celebrated its 20th anniversary with the discovery of the new largest known prime number. The new number, known as M74207281, is calculated by multiplying together 74.207.281 twos then subtracting one. It is almost 5 million digits larger than the previously calculated largest prime number, and is as long as you can hardly fit in a book with 9.000 pages!

The new largest known prime number, ladies and gentlemen, is 2^74,207,281-1 and has over 22 million digits.

An integer greater than one is called a prime number if its only divisors are one and itself. And if the prime number is in the form 2^P-1, where P is also a prime, then it is called a Mersenne prime. There are 50 known Mersenne primes. The letter “M” at the beginning of Mersenne primes is to honour Marin Mersenne, a French monk who lived between 1588 and 1648, working on number theory and these special prime numbers in particular.

GIMPS, founded in 1996 and has discovered all 15 of the largest known Mersenne primes since then, is a web-based Project where volunteers may participate by simply downloading a free program and race for an award. GIMPS' next major goal is to find a 100 million digit prime number, which will grant its discoverer an award of $150,000.