Primality proof for n = 10434257:
Take b = 2.
b^(n-1) mod n = 1.
13309 is prime. b^((n-1)/13309)-1 mod n = 8271012, which is a unit, inverse 4898857.
(13309) divides n-1.
(13309)^2 > n.
n is prime by Pocklington's theorem.