The list of prime numbers starts as follows:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37........
All other whole numbers are known as composite and can be written as the product of prime factors.
This is known as prime factorisation.
Examples
35 = 5 x 7
14 = 2 x 7
28 = 2 x 2 x 7
24 = 2 x 2 x 2 x 3
Writing 24 = 2 x 3 x 4 is correct but it is not a full prime factorisation because the 4 is not prime.