50000...00001 (2340-digits)

This number is a prime.

1 + 1 + 2 + 3 + 4 + ... + 10^1170, which is made of a 5, 1169 0s, a 5, 1168 0s and a 1 respectively is a proven prime. See proof. Is Sum[n,{n,1,10^1510}]+1 a provable prime? [Burns-Primo]