Divisors of 990: All 24 Factors

Divisors (Factors) Calculator

Use the calculator above to find all divisors (also called factors) of any positive integer up to 4,782,969. Beyond the divisor list, this tool also shows divisor pairs, the sum and count of divisors, prime factorization, and number properties (prime, perfect square, perfect number).

All Divisors of 990

The number 990 has 24 divisors:

1,  2,  3,  5,  6,  9,  10,  11,  15,  18,  22,  30,  33,  45,  55,  66,  90,  99,  110,  165,  198,  330,  495,  990

Divisor Pairs of 990

Each pair multiplies to 990:

Number of Divisors

The number 990 has 24 divisors, written as τ(990) = 24 in number theory.

Sum of Divisors

σ(990) = 1 + 2 + 3 + 5 + 6 + 9 + 10 + 11 + 15 + 18 + 22 + 30 + 33 + 45 + 55 + 66 + 90 + 99 + 110 + 165 + 198 + 330 + 495 + 990 = 2808

Prime Factorization of 990

See the full prime factorization calculator →

Properties of 990

• 990 is composite.
• 990 is not a perfect square.
• Number of divisors: 24.
• Sum of divisors: 2808.

Common Divisors with Another Number?

Looking for the divisors that 990 shares with another number? Use our Greatest Common Factor (GCF) calculator — it finds all common divisors and the largest one.

Step-by-Step: How to Find the Divisors of 990

An efficient way to find divisors uses the complementary pair trick: check each integer i from 1 to √990 ≈ 31.46. If i divides 990, then both i and 990/i are divisors.

1. 1 divides 990 (990 ÷ 1 = 990) → pair (1, 990)
2. 2 divides 990 (990 ÷ 2 = 495) → pair (2, 495)
3. 3 divides 990 (990 ÷ 3 = 330) → pair (3, 330)
4. 5 divides 990 (990 ÷ 5 = 198) → pair (5, 198)
5. 6 divides 990 (990 ÷ 6 = 165) → pair (6, 165)
6. 9 divides 990 (990 ÷ 9 = 110) → pair (9, 110)
7. 10 divides 990 (990 ÷ 10 = 99) → pair (10, 99)
8. 11 divides 990 (990 ÷ 11 = 90) → pair (11, 90)
9. 15 divides 990 (990 ÷ 15 = 66) → pair (15, 66)
10. 18 divides 990 (990 ÷ 18 = 55) → pair (18, 55)
11. 22 divides 990 (990 ÷ 22 = 45) → pair (22, 45)
12. 30 divides 990 (990 ÷ 30 = 33) → pair (30, 33)
13. Collect all unique values: {1, 2, 3, 5, 6, 9, 10, 11, 15, 18, 22, 30, 33, 45, 55, 66, 90, 99, 110, 165, 198, 330, 495, 990} — total 24 divisors.
14. Sum: 1 + 2 + 3 + 5 + 6 + 9 + 10 + 11 + 15 + 18 + 22 + 30 + 33 + 45 + 55 + 66 + 90 + 99 + 110 + 165 + 198 + 330 + 495 + 990 = 2808.

Nearby Examples

Related Operations for 990

• Multiples of 990 — "outward" complement; M is a multiple of 990 ⇔ 990 is a divisor of M
• 990 Prime Factorization — decompose into prime building blocks
• Find GCF of 990 and another number
• Find LCM of 990 and another number
• Is 990 a perfect square? (odd divisor count ⇔ yes)

See also our tables of divisors:

• Table of all divisors from 1 to 100
• Table of all divisors from 1 to 500
• Table of all divisors from 1 to 1,000
• Table of all divisors from 1 to 10,000

What Is a Divisor?

A divisor (also called a factor) of a positive integer n is any positive integer d such that n ÷ d has no remainder. In other words, d divides n evenly.

Every positive integer n has at least two divisors: 1 and n itself (with 1 being the trivial case of having only itself). Numbers with exactly 2 divisors are prime; numbers with 3 or more divisors are composite.

Why use this calculator? Beyond just listing divisors, this tool computes the sum σ(n), the count τ(n), prime factorization, divisor pairs (useful for visual learners and factoring problems), and detects whether n is a prime, a perfect square, or a perfect number.

References

• [1] Divisor (Wikipedia)
• [2] Divisor function (Wikipedia)
• [3] Divisor (Wolfram MathWorld)

Divisors Calculation Examples

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