Mathematicians at UCLA believe they have found a very long and very special prime number: It clocks in at nearly 13 million digits, and belongs to an elite group of numbers called Mersenne primes. If the math checks out, the discovery will win UCLA’s math department a $100,000 prize that was offered for the first Mersenne prime found with over 10 million digits.
Primes are numbers like three, seven and 11 that are divisible by only two whole positive numbers: themselves and one. Mersenne primes — named for their discoverer, 17th century French mathematician Marin Mersenne — are expressed as 2P-1, or two to the power of “P” minus one. P is itself a prime number. For the new prime, P is 43,112,609 [AP].