Primality proof for n = 5071793:
Take b = 2.
b^(n-1) mod n = 1.
28817 is prime. b^((n-1)/28817)-1 mod n = 1529467, which is a unit, inverse 1101785.
(28817) divides n-1.
(28817)^2 > n.
n is prime by Pocklington's theorem.