How to tell whether its a prime or composite number

Prime numbers have only 2 factors 1 and its number for example:

2, 3, 5, 7, 11, 13, 17, 19, 23

Like this 1*2. Or 3*1

Composite numbers have more than two factors for example:

0, 4, 6, 8, 9, 10, 12, 14 15, 16 ...

For example 0 has many factors

0 times 3 0times 4