Take b = 2.

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

29611 is prime.

b^((n-1)/29611)-1 mod n = 748474921, which is a unit, inverse 150806420.

13 is prime.

b^((n-1)/13)-1 mod n = 178262577, which is a unit, inverse 931669981.

(13^2 * 29611) divides n-1.

(13^2 * 29611)^2 > n.

n is prime by Pocklington's theorem.