▣ CALCULATORS Updated July 25, 2026

Prime Number Checker

Test primality and list factors instantly.

Number
Result
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How it works

Primality is tested by trial division up to the square root of the number, which is exact and fast for the values a browser can hold.

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Frequently asked questions

Is 1 a prime number?

No. A prime has exactly two distinct divisors, and 1 only has one.

What does the factor list show?

Every prime factor with its multiplicity, so 360 shows 2 x 2 x 2 x 3 x 3 x 5.

Comments

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