Factors & multiples explorer
Enter any whole number from 2 to 500 to watch its factor tree branch down to prime factors, or compare two numbers to see their common factors highlighted, with the GCF and LCM computed and shown visually. Every answer is computed in code, so it is never wrong. Free, no sign-up.
Factor tree for 24
Each branch splits into two factors that multiply back to the number above, down to its prime factors (shaded).
All 8 factors of 24
- 24 is composite - it has 8 factors in total.
About this tool
Factors, multiples and divisibility are core Years 4 to 6 number topics: finding all the factors of a number, spotting whether one number divides another, and using a step-by-step process (like a factor tree) to explore the patterns rather than just computing a single answer. This tool is built for exactly that kind of exploration - change the numbers and watch how the tree and the common-factor highlighting change with them.
Frequently asked questions
What is a factor tree?
A factor tree starts with a number and splits it into two factors that multiply back to it, then keeps splitting each branch until every branch ends in a prime number. Multiplying all the prime numbers at the ends of the branches together always gives back the original number.
What is the difference between the GCF and the LCM?
The greatest common factor (GCF, also called the HCF) is the largest number that divides evenly into both numbers. The lowest common multiple (LCM) is the smallest number that both numbers divide evenly into. The GCF is always less than or equal to the smaller number; the LCM is always greater than or equal to the larger number.
Why do some numbers have an odd number of factors?
Factors normally pair up (for 12: 1x12, 2x6, 3x4). A perfect square, like 36, has one factor that pairs with itself (6x6), so its factor list has an odd number of entries.