Question

What are the factors of 23? Is 23 prime or composite?

Answer 1

`23` has only 2 factors - it is prime.

Explanation:

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.

Answer 2

The number `23`, has only two factors (`1` and itself), meaning that it is a prime number - not composite.

Explanation:

We can first figure out whether a number is prime or composite purely by decomposing it into a "prime factorization". You are normally able to do this using a scientific calculator such as the Casio fx-82ES PLUS, however, you can also use a factor tree.

If the prime decomposition has only the number, then it is prime:

P(d) = `23`

All the best!