Primality proof for n = 748169:

Take b = 2.

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

2281 is prime.
b^((n-1)/2281)-1 mod n = 628215, which is a unit, inverse 53683.

(2281) divides n-1.

(2281)^2 > n.

n is prime by Pocklington's theorem.