Primality proof for n = 187019741:

Take b = 2.

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

9350987 is prime.
b^((n-1)/9350987)-1 mod n = 1048575, which is a unit, inverse 44930397.

(9350987) divides n-1.

(9350987)^2 > n.

n is prime by Pocklington's theorem.