68476...55383 (35-digits)

This number is a prime.

                                      68476 5627633278 5435908559 9065855383

2^(2+3*5*7)+3^(3+2*5*7)+5^(5+2*3*7)+7^(7+2*3*5) is prime. Note also that all the exponents (37, 47, 73, and 107) are also prime. [Rupinski]