Enter a number in the Number #1 field to see all its divisors. Add a second number in Number #2 to compare the divisors of both and find their common divisors. Accepts positive integers only.
Find the divisors
Divisors of one or two numbers
Positive integers only. Number #2 is optional — fill it in to see common divisors.
How to use the calculator
- In the Number #1 field, enter the number whose divisors you want to find.
- If you want to compare with a second number, also fill in Number #2 (optional).
- Click Calculate. The calculator will show all divisors of each number and, if two numbers are provided, the common divisors between them.
- To start a new calculation, click Clear.
What is a divisor
An integer d is a divisor of an integer n when dividing n by d leaves no remainder, that is:
n mod d = 0
In this case, we say that n is divisible by d, or that d is a factor of n. For example, the divisors of 12 are: 1, 2, 3, 4, 6 and 12.
Divisibility rules
To quickly identify some divisors, use the most common divisibility rules:
| Divisor | Rule |
|---|---|
| 2 | The last digit is even (0, 2, 4, 6 or 8) |
| 3 | The sum of digits is divisible by 3 |
| 4 | The last two digits form a number divisible by 4 |
| 5 | The last digit is 0 or 5 |
| 6 | It is divisible by both 2 and 3 |
| 9 | The sum of digits is divisible by 9 |
| 10 | The last digit is 0 |
Frequently asked questions about divisors
What is a divisor of a number?
An integer d is a divisor of an integer n if dividing n by d leaves no remainder. For example, the divisors of 12 are 1, 2, 3, 4, 6 and 12.
How do you find all divisors of a number?
To find all divisors of n, test every integer from 1 to n and check whether the remainder is zero. A more efficient method is to test only up to the square root of n: if d divides n, then n/d is also a divisor.
What are common divisors of two numbers?
Common divisors of two numbers a and b are values that divide both a and b without a remainder. The greatest of them is the GCD. For example, the common divisors of 12 and 18 are 1, 2, 3 and 6, and GCD(12, 18) = 6.
Does every integer have at least one divisor?
Yes. Every non-zero integer n has at least two positive divisors: 1 and |n|. Prime numbers have exactly two positive divisors: 1 and themselves.
What is the difference between a divisor and a multiple?
If d is a divisor of n, then n is a multiple of d. The relationship is inverse: divisors of n are numbers that divide n exactly, while multiples of n are numbers that n divides exactly.
See also…
