Is 22 prime or composite??

2 Answers
May 7, 2018

22 is composite.

Explanation:

First, review what "prime" and "composite" mean:

A prime number is number greater than 1 that can't be created by multiplying two smaller, natural numbers.

A composite number is a number greater than 1 that can be created by multiplying two smaller, natural numbers.

Let's factor 22:

1 - 22
2 - 11

Because 22 can be formed by multiplying two smaller, natural numbers, it is composite.

Source:
https://en.wikipedia.org/wiki/Prime_number

May 9, 2018

22 is composite because it has four factors.

Explanation:

A Prime number has only 2 factors - 1 and itself.

The only even number which is prime is 2, since 2=1×2
All other even numbers are multiples of 2 and therefore have 2 as a factor.

22=1×22 and22=2×11
Therefore we can see it has 4 factors and cannot be prime, it is composite.

Numbers which have more than 2 factors are composite numbers,

1 is neither prime nor composite since it has only 1 factor.

The prime numbers less than 30 are:

2,3,5,7,11,13,17,19,23,29