Prime Number Checker

Enter any number and find out if it's prime or composite. You also get its full list of factors, the prime factorization, and the nearest primes on either side. Works up to a million.

How to use

  1. Type in any whole number up to 1,000,000.
  2. The result tells you immediately whether it's prime or composite.
  3. Scroll down to see all factors, the prime factorization, and which primes are closest to it.

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Permutation & CombinationProbability CalculatorScientific Calculator