Factor Calculator guide
Factor Calculator: All Factors and Factor Pairs
Use our factor calculator to list every factor of a number, its factor pairs, how many factors it has and its prime factorisation.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
Factors are numbers that divide exactly into another number. Our Factor Calculator lists all of them, in order and as pairs.
How to use the calculator (Factor Calculator)
Enter a whole number. You'll see:
- Every factor, from smallest to largest
- The factor pairs that multiply to give the number
- How many factors it has and their sum
- Its prime factorisation, and whether it's prime or perfect
How it works
The calculator checks every number up to the square root of your number. Each one that divides exactly gives a factor pair.
A worked example
With the calculator's default settings, 60 has 12 factors: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30 and 60.
The factor pairs are 1 × 60, 2 × 30, 3 × 20, 4 × 15, 5 × 12 and 6 × 10.
Special numbers
| Type | Meaning | Example |
|---|---|---|
| Prime | Exactly two factors | 7, 13, 29 |
| Square | An odd number of factors | 36, 49 |
| Perfect | Factors (excluding itself) add up to it | 6, 28, 496 |
Frequently asked questions
What's the difference between factors and multiples?
Factors go into a number; multiples come out of it. 3 is a factor of 12, and 12 is a multiple of 3.
Is 1 a prime number?
No. A prime has exactly two factors, and 1 has only one.
How do I find the number of factors quickly?
From the prime factorisation, add 1 to each power and multiply. 60 = 2² × 3 × 5, so it has 3 × 2 × 2 = 12 factors.
For the prime factors only, use our Prime Factorization Calculator.
Sources and further reading
- GOV.UK: National curriculum in England – mathematicsgov.uk
- Wolfram MathWorld: Divisormathworld.wolfram.com
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.