Square Root Calculator › Square root of 666
Square Root of 666
√666 ≈ 25.806976
666 is not a perfect square, so √666 is an irrational number that is approximately 25.806976. In simplified radical form, √666 = 3√74.
√666 lies between √625 = 25 and √676 = 26.
| Number | 666 |
| Square root (decimal) | 25.806976 |
| Simplified radical | 3√74 |
| Perfect square? | No |
| Rational? | No |
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Frequently asked questions
Is 666 a perfect square?
No, 666 is not a perfect square, so its square root is irrational and approximately 25.806976.
What is the square root of 666 in simplest radical form?
√666 = 3√74 in simplest radical form.