Factors of 121

How to find the factors of 121

Test every whole number from 1 up to the square root of 121 (√121 ≈ 11.000). Each number that divides evenly gives you two factors at once: the divisor and the quotient.

• 121 ÷ 1 = 121 — so 1 and 121 are factors
• 121 ÷ 2 = 60.5 — not a whole number
• 121 ÷ 3 = 40.333 — not a whole number
• 121 ÷ 4 = 30.25 — not a whole number
• 121 ÷ 5 = 24.2 — not a whole number
• 121 ÷ 6 = 20.167 — not a whole number
• 121 ÷ 7 = 17.286 — not a whole number
• 121 ÷ 8 = 15.125 — not a whole number
• 121 ÷ 9 = 13.444 — not a whole number
• 121 ÷ 10 = 12.1 — not a whole number
• 121 ÷ 11 = 11 — so 11 and 11 are factors

Collecting both numbers from every successful division gives the complete list: 1, 11 and 121.

Prime factorization of 121

Divide by the smallest prime that fits, and keep going until the quotient is 1:

The primes you divided by give 121 = 11². From the exponents you can also count the factors without listing them: (2 + 1) = 3.

Properties of 121

• 121 is a composite number.
• The sum of all its factors is 133; the sum of its proper factors (excluding 121) is 12, which makes it a deficient number (its proper factors add up to less than itself).
• 121 is a perfect square: 11 × 11. Perfect squares always have an odd number of factors.
• Multiples of 121 include 242, 363, 484, 605 and so on.

Factors vs. multiples

Factors of 121 are the numbers that divide into it; multiples of 121 are the numbers it divides into. Every number has a limited set of factors but infinitely many multiples. To work with any other number, use the factors calculator, or find shared factors with the GCF calculator.