Square Root of 21
The square root of 21 is approximately 4.582576, or exactly √21 in simplified radical form. No, 21 is not a perfect square. Its square root is irrational and never terminates or repeats as a decimal.
√21
4.582576
Simplified Radical Form
√21
Perfect Square
No
√21 is irrational — its decimal form (4.582576) never terminates or repeats. The simplified radical form (√21) is the exact value.
Frequently Asked Questions
What is the square root of 21?
The square root of 21 is approximately 4.582576, or exactly √21 in simplified radical form.
Is 21 a perfect square?
No, 21 is not a perfect square. Its square root is irrational and never terminates or repeats as a decimal.
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