Primality proof for n = 163131120638915058577002756917:

Take b = 2.

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

760192948315673 is prime.
b^((n-1)/760192948315673)-1 mod n = 145847107365479093624900908603, which is a unit, inverse 145881772526240962556179613612.

(760192948315673) divides n-1.

(760192948315673)^2 > n.

n is prime by Pocklington's theorem.