Last updated October 8, 2026 · Report an error
Every whole number has a specific set of factors — numbers that divide it evenly with no remainder — and listing them all only requires checking divisibility up to the number's square root.
This calculator lists every factor of a number, along with the factor count, sum, and whether it's prime.
How it works
Enter a number. The calculator checks every integer from 1 up to the square root of the number — whenever one divides evenly, both it and its complementary factor are added to the list, which is then sorted from smallest to largest.
- Enter number.
- Click Calculate to see your results.
Examples
Factors of 60
60 has 12 factors: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60, which sum to 168.
Who should use it
- Finding all divisors of a number for a number theory or math course.
- Checking whether a specific number is prime.
Industry applications
- Mathematics education
- Number theory and computer science coursework
Advantages
- Lists every factor, not just the prime ones.
- Also reports the sum of factors and a direct prime/not-prime verdict.
Limitations
- Very large numbers with a small smallest prime factor can take noticeably longer to fully factor.
Common mistakes to avoid
- Assuming factor count and prime factor count are the same thing — they're usually very different (60 has 12 factors but only 3 distinct prime factors).
- Forgetting that 1 and the number itself always count as factors.
Best practices
- Use this tool when you need every divisor of a number (like for simplifying fractions or finding common factors); use Prime Factorization when you specifically need the prime building blocks.
Tips
- The sum of a number's factors (excluding itself) equaling the number itself defines a "perfect number" — 6 (1+2+3=6) and 28 are the two smallest examples, a fun pattern to check with this tool.
Frequently asked questions
Yes, with no signup and no limit on how many numbers you check.
Prime factorization breaks a number down into only its prime building blocks (like 60 = 2² × 3 × 5); this calculator lists every factor, prime or not — all 12 divisors of 60, not just its 3 distinct prime factors.
Factors always come in pairs that multiply to the original number — once you've checked past the square root, every remaining factor has already been found as the pair of a smaller one, so checking further would just find duplicates.
A prime number has exactly 2 factors (1 and itself) — if the factor count shown is 2, the number is prime, which the tool also states directly.