The number 33 is not a prime number. Prime numbers only have factors of themselves and 1. The positive factors of 33 are 1, 3, 11 and 33.
The number 33 is what mathematicians call a composite number. A composite number is any number that has more factors than itself and 1. The only whole number that is not prime or composite is the number 1. Because 33 is a composite number, it has a prime factorization or a set of factors that are all prime.
To find the prime factorization of a number, divide by the smallest prime numbers first. Since 33 is odd, it does not divide by 2, but is does divide evenly into 3 x 11. Since 11 is also prime, this means the prime factorization of 33 is 3 x 11.