Maths

As for example, take number $11$ .

Factors of $11$ are $1$ and $11$

Therefore, $11$ is a prime number.

Examples of composite number are $8$ , $10$ , $12$ .

Factors of $8$ are $1,2,8$

For example :-

Divisors of $6$ are $1,2,3$ and $6$

Perfect divisors of $6$ are $1,2$ and $3$

And $6=1+2+3$

So, $6$ is a perfect square.