Primality proof for n = 7207:

Take b = 2.

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

1201 is prime.
b^((n-1)/1201)-1 mod n = 63, which is a unit, inverse 572.

(1201) divides n-1.

(1201)^2 > n.

n is prime by Pocklington's theorem.