Factors of 121

All factors of 121

Here are all 3 factors of 121, listed from smallest to largest.

Factor pairs of 121

These 2 pairs of whole numbers each multiply to give 121.

Notice the pair (11, 11) — because 121 is a perfect square, this pair uses the same number twice.

Prime factorization of 121

Dividing 121 by the smallest prime at each step gives its prime factorization:

The distinct prime factors of 121 are 11. To factorize any other number, use the prime factorization calculator.

Factor tree of 121

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

Properties of 121

What makes 121 interesting

• 121 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.
• 121 is a perfect square: 11 × 11 = 121. This is why it has an odd number of factors (3) — the pair (11, 11) counts only once.
• 121 is a deficient number: its proper factors sum to 12, which is 109 less than 121 itself.
• 121 is a prime power: it is 11 raised to the power of 2. All of its factors are powers of 11.

How to find the factors of 121 yourself

Divide 121 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 √121 ≈ 11.00, because every factor above that pairs with one below it.

Reading both columns gives every factor: 1, 11, 121. The factor calculator does this automatically for any number.