A megaprime is a prime number with at least one million decimal digits[1] (whereas titanic prime is a prime number with at least 1000 digits, and gigantic prime has at least 10000 digits).
As of 25 December 2011[update], 41 megaprimes are known.[2] The first to be found was the Mersenne prime 26972593−1 with 2,098,960 digits, discovered in 1999 by Nayan Hajratwala, a participant in the distributed computing project GIMPS.[3][4]
The term bevaprime has also been proposed as a term for a prime with at least 1,000,000,000 digits.[4]