Primality proof for n = 8463023:
Take b = 2.
b^(n-1) mod n = 1.
37447 is prime. b^((n-1)/37447)-1 mod n = 4062265, which is a unit, inverse 6862566.
(37447) divides n-1.
(37447)^2 > n.
n is prime by Pocklington's theorem.