Primality proof for n = 71263:

Take b = 2.

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

107 is prime.
b^((n-1)/107)-1 mod n = 5675, which is a unit, inverse 61192.

37 is prime.
b^((n-1)/37)-1 mod n = 24360, which is a unit, inverse 10511.

(37 * 107) divides n-1.

(37 * 107)^2 > n.

n is prime by Pocklington's theorem.