Primality proof for n = 9816177919:

Take b = 2.

b^(n-1) mod n = 1.

514313 is prime.
b^((n-1)/514313)-1 mod n = 4147490218, which is a unit, inverse 4389308354.

(514313) divides n-1.

(514313)^2 > n.

n is prime by Pocklington's theorem.