Factor Calculator
A factor is a whole number that divides another number evenly. This calculator lists every factor of your number in order, counts them, shows the prime factorization, and tells you whether the number is prime — the building blocks behind simplifying fractions, finding common denominators and much of number theory.
Results
Formula
How to use this calculator
- Enter a whole number.
- Press Calculate.
- Read the full factor list, the factor count and the prime factorization.
Worked example
Find the factors of 36.
- Pairs: 1 × 36, 2 × 18, 3 × 12, 4 × 9, 6 × 6.
- Collect them in order: 1, 2, 3, 4, 6, 9, 12, 18, 36.
- Prime factorization: 36 = 2 × 2 × 3 × 3.
Result: 36 has 9 factors and is composite.
Frequently asked questions
What is the difference between factors and multiples?
Factors divide into a number (36 has nine factors). Multiples are what you get multiplying by whole numbers (36, 72, 108…) — there are infinitely many.
Is 1 a prime number?
No. By definition a prime has exactly two factors, 1 and itself. The number 1 has only one factor, so it is neither prime nor composite.
Why does every number have a unique prime factorization?
That is the Fundamental Theorem of Arithmetic: every whole number above 1 breaks into primes in exactly one way, which is why prime factorization is so useful.
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