Megaprime

A megaprime is a prime number with at least one million decimal digits.

[7] 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.

All numbers from 10999999 through 10999999 + 593498 are known to be composite, and there is a very high probability that 10999999 + 593499, a strong probable prime for each of 8 different bases, is the smallest megaprime.

As of 2024[update], the biggest prime number known to not be a megaprime is 10999999 - 1022306×10287000 - 1.

There is a very high probability that 10999999 − 172473 is the biggest non-mega prime.