# Is 22 prime or composite??

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.

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 $2 = 1 \times 2$
All other even numbers are multiples of $2$ and therefore have $2$ as a factor.

$22 = 1 \times 22 \text{ } \mathmr{and} 22 = 2 \times 11$
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:

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