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What is the Square Root of 399?

The square root of 399 is 19.9749843554. Calculate another value or review the exact form, nearby perfect powers, and verification.

Answer

Square Root√399 = 19.9749843554
CalculatedNon-perfect squareIrrational
Exact form√399
Perfect squareNo
Number typeIrrational
Verification19.97498435542 ≈ 399

On this page

How the answer is calculated

We solve x2 = 399. The resulting value is x = 19.9749843554.

Verification: 19.97498435542 ≈ 399.

Simplified radical form

The square root of 399 in simplified radical form is √399.

There are no square factors that can be taken outside the radical, so √399 is already in simplest radical form.

Nearest Perfect squares

PositionBaseValue
Lower or equal19361
Upper or equal20400

Nearby square roots

NumberSquare root
√39619.8997487421
√39719.9248588452
√39819.9499373433
√39919.9749843554
√40020
√40120.0249843945
√40220.0499376558

Number properties

Is 399 a perfect square?

No. Its square root is not a whole number.

Is the square root rational or irrational?

√399 is irrational because 399 is not a perfect square.

Visual guide

Square Root function graph

See how the result changes as the input moves across positive and negative values. Square roots are shown for non-negative inputs; cube roots continue through negative inputs.

Common questions

Frequently asked questions

It asks for the number that, when raised to the power of 2, equals 399.