What is the prime factorization of 1260

There are 36 factors of 1260:

1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 14, 15, 18,
20, 21, 28, 30, 35, 36, 42, 45, 60, 70, 84, 90,
105, 126, 140, 180, 210, 252, 315, 630, 1260.

To find the factors of a positive integer, factor it first into product of primes. In this case, 1260 = 2^2 * 3^2 * 5 * 7. Each of its factors is a product of some power of 2 (exponents 0,1,or 2), some powers of 3 (exponents 0, 1, or 2), 5 or no 5, 7 or no 7. So there are totally 3*3*2*2=36 of them.