This number is a prime.
6866683 is prime, 6+866683 is prime, 68+66683 is prime, 686+6683 is prime, 6866+683 is prime, 68666+83 is prime, and 686668+3 is too. [Eitzen]
6866683 is prime, 6+866683 is prime, 68+66683 is prime,
686+6683 is prime, 6866+683 is prime, 68666+83 is prime,
and 686668+3 is too. [Eitzen]