About this calculator
Enter a whole number to see its prime factors.
How to use it
- Enter a whole number.
- Read its prime factors.
The formula
Divide by the smallest prime repeatedly until 1 is left
- number of divisors
- product of (power + 1) for each prime
Worked example
360
- 360 = 2 × 2 × 2 × 3 × 3 × 5 = 2³ × 3² × 5.
- It has (3+1)(2+1)(1+1) = 24 divisors, which add up to 1,170.
What the result means
Prime factors make HCF and LCM easy: take the lowest or highest power of each prime.
Assumptions
- Whole numbers from 2 to 10¹².
Limitations
- Very large numbers take longer to factor.
Frequently asked questions
What are the prime factors of 100?
2² × 5².
How many divisors does 360 have?
24.
Why is factorization unique?
By the fundamental theorem of arithmetic.
Last reviewed on 3 October 2026. Found a mistake? Tell us.