Megaprime

A megaprime is a prime number with at least one million decimal digits (whereas titanic prime is a prime number with at least 1,000 digits, and gigantic prime has at least 10,000 digits).

As of January 2016, 164 (probable) megaprimes are known, including 150 definitely primes and 14 probable primes. The first to be found was the Mersenne prime 2−1 with 2,098,960 digits, discovered in 1999 by Nayan Hajratwala, a participant in the distributed computing project GIMPS.