Primality proof for n = 9801157:

Take b = 2.

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

816763 is prime.
b^((n-1)/816763)-1 mod n = 4095, which is a unit, inverse 543312.

(816763) divides n-1.

(816763)^2 > n.

n is prime by Pocklington's theorem.