# What is the square root of 21

The short answer is $$\sqrt{ 21 } = 4.5825756949558$$.

If that's all you're looking for, thanks for coming by. But if you're interested in the hows and whys behind square roots, continue reading and we'll tell you all about the square root of 21.

## 21 is not a perfect square

Let's look at some math

$$\LARGE \sqrt{ 21 } = 4.5825756949558$$

Note that $$4.5825756949558$$ is not a whole number, therefore 21 is not a perfect square.

The next perfect square greater than 21 is 25. The previous perfect square less than 21 is 16.

## Square root of 21 as an exponent

Any square root can be converted to a number with a fractional exponent. In the case of 21 the following two values are equal.

$$\LARGE \sqrt{ 21 } = 21^{^1/_2}$$

## Square root of 21 as a fraction

Since 21 is not a perfect square, sometimes we might want to get a fractional estimate of the square root value. In the case of 21 that value is $$\Large 4 \frac{60}{103}$$.

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