Factors of 55

All factors of 55

Here are all 4 factors of 55, listed from smallest to largest.

Factor pairs of 55

These 2 pairs of whole numbers each multiply to give 55.

Prime factorization of 55

Dividing 55 by the smallest prime at each step gives its prime factorization:

The distinct prime factors of 55 are 5, 11. To factorize any other number, use the prime factorization calculator.

Factor tree of 55

A factor tree shows the same prime factorization visually. Each composite branch splits until every endpoint is a prime number.

Properties of 55

What makes 55 interesting

• 55 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 2 different ways.
• 55 is a deficient number: its proper factors sum to 17, which is 38 less than 55 itself.
• 55 appears in the Fibonacci sequence, where each number is the sum of the two before it.
• 55 is a triangular number — it is the sum of the first 10 whole numbers (1 + 2 + … + 10 = 55).

How to find the factors of 55 yourself

Divide 55 by each whole number starting from 1. Whenever the division leaves no remainder, both the divisor and the quotient are factors. You only need to test up to √55 ≈ 7.42, because every factor above that pairs with one below it.

Reading both columns gives every factor: 1, 5, 11, 55. The factor calculator does this automatically for any number.