Prime Numbers

Prime number
A prime number has exactly two different factors, 1 and itself.
Example 1:
7 = 1 × 7. The number 7 is only divisible by 1 and itself 7, so the number 7 is a prime number.
Example 2:
11 = 1 × 11. The number 11 is only divisible by 1 and itself 11, so the number 11 is a prime number.
Example 3:
10 = 1 × 10, 10 = 2 × 5. Since the number 10 is divisible by 1, 2, 5, 10. So the number 10 is not a prime number.
Note:
A prime number has exactly 2 factors, 1 and itself, for example, 7 and 11 are prime numbers.
Since 10 = 1 × 10 and 10 = 2 × 5, so 10 is a composite number, it has 4 factors. 10 is not a prime number.