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Prime Factor Calculator.

Find the prime factors of a non-zero integer.

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Set your values

Results update as you type.

Factorization: 2 × 2 × 2 × 3 × 3 × 5

Factorization

2 × 2 × 2 × 3 × 3 × 5
Prime factors: 2 × 2 × 2 × 3 × 3 × 5

Prime factors

2 × 2 × 2 × 3 × 3 × 5

Results update automatically as you type.

Use Cases

Simplify fractions

Find the prime factors of numerator and denominator to simplify fractions easily.

Example: Factor 24 and 36 to simplify 24/36 to 2/3.

Find greatest common divisor (GCD)

Use prime factorization to determine the GCD of two numbers by comparing their prime factors.

Example: Factor 48 and 180 to find GCD = 12.

Frequently Asked Questions

What is a prime factor?
A prime factor is a factor of a number that is a prime number (only divisible by 1 and itself). For example, the prime factors of 12 are 2 and 3, because 12 = 2 × 2 × 3.
How do I use this calculator?
Simply enter any non-zero integer in the 'Integer' field and click calculate. The calculator will break down the number into its prime factors, showing the product of primes that equals your input.
Can I factor negative numbers?
Yes, you can enter negative integers. The calculator will factor the absolute value and include -1 as a factor to account for the negative sign.

Tips & Common Mistakes

Tips

  • Start with the smallest prime number (2) and divide repeatedly until the quotient is 1.
  • If the number is even, it has 2 as a prime factor; if the sum of digits is divisible by 3, it has 3 as a factor.
  • For large numbers, use a factor tree or this calculator to avoid missing prime factors.
  • Remember that 1 has no prime factors, and 0 is not allowed as input.

Common Mistakes to Avoid

  • Entering 0, which is not allowed; the calculator only accepts non-zero integers.
  • Confusing prime factors with all factors; prime factors are only the prime numbers that multiply to the original number.
  • Forgetting to include repeated prime factors, such as 2×2 for 4, not just 2.

Last updated: August 13, 2026