Question

Write all the factors of $21$ ?

Answer 1

Finding the factors of $21$:

Factor: A Factor of a number is an exact divisor of that number.

The given number is $21$

Here,

$$\begin{gathered} 21÷\; 1\; =21, \\ 21÷\; 3\; =7, \\ 21÷7=3, \\ 21÷21=\; 1 \end{gathered}$$

Clearly, $21$ is exactly divisible by $1,3,7,21$

Hence, all the factors of $21$ are $1,3,7,21$