##23## has only 2 factors – it is prime.

A prime number can be defined as:

“A natural number which has only 2 factors – itself and 1”.

23 has only 2 factors:##” “23 = 1 xx23##

There are no other natural numbers which are factors. ##23## is therefore a prime number.

If it had 3 or more factors it would be composite.

1 is the only number which has 1 factor – it is neither prime nor composite.