23571...76221 (141-digits)

This number is a prime.

                                                                           2
3571317193 1618910712 7521607127 9220322813 2174253442 3968999411 1213199372
1701232094 4497862431 1050313204 9216091756 8398594331 2577871398 2692976221

The concatenation of the exponents of the first 36 Mersenne primes yields this large prime number. [Hartley]