Factors of 990

How to find the factors of 990

Test every whole number from 1 up to the square root of 990 (√990 ≈ 31.464). Each number that divides evenly gives you two factors at once: the divisor and the quotient.

• 990 ÷ 1 = 990 — so 1 and 990 are factors
• 990 ÷ 2 = 495 — so 2 and 495 are factors
• 990 ÷ 3 = 330 — so 3 and 330 are factors
• 990 ÷ 4 = 247.5 — not a whole number
• 990 ÷ 5 = 198 — so 5 and 198 are factors
• 990 ÷ 6 = 165 — so 6 and 165 are factors
• 990 ÷ 7 = 141.429 — not a whole number
• 990 ÷ 8 = 123.75 — not a whole number
• 990 ÷ 9 = 110 — so 9 and 110 are factors
• 990 ÷ 10 = 99 — so 10 and 99 are factors
• 990 ÷ 11 = 90 — so 11 and 90 are factors
• 990 ÷ 12 = 82.5 — not a whole number
• 990 ÷ 13 = 76.154 — not a whole number
• 990 ÷ 14 = 70.714 — not a whole number
• 990 ÷ 15 = 66 — so 15 and 66 are factors
• 990 ÷ 16 = 61.875 — not a whole number
• 990 ÷ 17 = 58.235 — not a whole number
• 990 ÷ 18 = 55 — so 18 and 55 are factors
• 990 ÷ 19 = 52.105 — not a whole number
• 990 ÷ 20 = 49.5 — not a whole number
• 990 ÷ 21 = 47.143 — not a whole number
• 990 ÷ 22 = 45 — so 22 and 45 are factors
• 990 ÷ 23 = 43.043 — not a whole number
• 990 ÷ 24 = 41.25 — not a whole number
• 990 ÷ 25 = 39.6 — not a whole number
• 990 ÷ 26 = 38.077 — not a whole number
• 990 ÷ 27 = 36.667 — not a whole number
• 990 ÷ 28 = 35.357 — not a whole number
• 990 ÷ 29 = 34.138 — not a whole number
• 990 ÷ 30 = 33 — so 30 and 33 are factors
• 990 ÷ 31 = 31.935 — not a whole number

Collecting both numbers from every successful division gives the complete list: 1, 2, 3, 5, 6, 9, 10, 11, 15, 18, 22, 30, 33, 45, 55, 66, 90, 99, 110, 165, 198, 330, 495 and 990.

Prime factorization of 990

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

The primes you divided by give 990 = 2 × 3² × 5 × 11. From the exponents you can also count the factors without listing them: (1 + 1) × (2 + 1) × (1 + 1) × (1 + 1) = 24.

Properties of 990

• 990 is a composite number.
• The sum of all its factors is 2,808; the sum of its proper factors (excluding 990) is 1,818, which makes it a abundant number (its proper factors add up to more than itself).
• 990 is not a perfect square, so its factors pair up evenly.
• Multiples of 990 include 1,980, 2,970, 3,960, 4,950 and so on.

Factors vs. multiples

Factors of 990 are the numbers that divide into it; multiples of 990 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.