Prime Number Checker

Check whether a number is prime, show its prime factorisation and the next prime.

Enter values

Number

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trial division up to √n

All calculations run locally in your browser and update instantly as you type.

What is a prime number?+

A prime is a whole number greater than 1 whose only divisors are 1 and itself — for example 2, 3, 5, 7 and 11.

All calculations run locally in your browser. Nothing you type is sent to a server.