Primality proof for n = 80897:
Take b = 3.
b^(n-1) mod n = 1.
79 is prime.
b^((n-1)/79)-1 mod n = 62063, which is a unit, inverse 15871.
2 is prime.
b^((n-1)/2)-1 mod n = 80895, which is a unit, inverse 40448.
(2^10 * 79) divides n-1.
(2^10 * 79)^2 > n.
n is prime by Pocklington's theorem.