Primality proof for n = 188353237:
Take b = 2.
b^(n-1) mod n = 1.
1613 is prime.
b^((n-1)/1613)-1 mod n = 37935592, which is a unit, inverse 82301414.
263 is prime.
b^((n-1)/263)-1 mod n = 173728644, which is a unit, inverse 125789862.
(263 * 1613) divides n-1.
(263 * 1613)^2 > n.
n is prime by Pocklington's theorem.