NOT JUST ANY PRIME

Mersenne primes are a special
class of prime, and they have a particular formula.

2^n - 1
The number n is a prime, and the result is prime. And what makes the Mersenne primes so interesting is how rare they are. And their gargantuan size.

Ancient Greek mathematicians were the first to describe Mersenne primes, and, up until now, only 46 had been discovered. This most recent one — though not the largest — is a whopper at nearly 13 million digits long. Please, click here to read the whole article.