Divisors of 20: All 6 Factors
Quick Answer
20 has 6 divisors (factors): 1, 2, 4, 5, 10, 20.
Sum: 42.
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 20
The number 20 has 6 divisors:
1, 2, 4, 5, 10, 20
Divisor Pairs of 20
Each pair multiplies to 20:
| Factor 1 | × | Factor 2 | = | Product |
|---|---|---|---|---|
| 1 | × | 20 | = | 20 |
| 2 | × | 10 | = | 20 |
| 4 | × | 5 | = | 20 |
Number of Divisors
The number 20 has 6 divisors, written as τ(20) = 6 in number theory.
Sum of Divisors
σ(20) = 1 + 2 + 4 + 5 + 10 + 20 = 42
Prime Factorization of 20
Properties of 20
- 20 is composite.
- 20 is not a perfect square.
- Number of divisors: 6.
- Sum of divisors: 42.
Common Divisors with Another Number?
Looking for the divisors that 20 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 20
An efficient way to find divisors uses the complementary pair trick: check each integer i from 1 to √20 ≈ 4.47. If i divides 20, then both i and 20/i are divisors.
- 1 divides 20 (20 ÷ 1 = 20) → pair (1, 20)
- 2 divides 20 (20 ÷ 2 = 10) → pair (2, 10)
- 4 divides 20 (20 ÷ 4 = 5) → pair (4, 5)
- Collect all unique values: {1, 2, 4, 5, 10, 20} — total 6 divisors.
- Sum: 1 + 2 + 4 + 5 + 10 + 20 = 42.
Related Operations for 20
- Multiples of 20 — "outward" complement; M is a multiple of 20 ⇔ 20 is a divisor of M
- 20 Prime Factorization — decompose into prime building blocks
- Find GCF of 20 and another number
- Find LCM of 20 and another number
- Is 20 a perfect square? (odd divisor count ⇔ yes)
See also our tables of divisors:
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.
Divisors Calculation Examples
Find all divisors of these numbers:
Related Calculators
- Multiples of a Number — "outward" complement
- Prime Factorization — product of prime divisors
- Greatest Common Factor (GCF) — largest common divisor of 2+ numbers
- Least Common Multiple (LCM) — smallest common multiple
- Is N a Perfect Square? — odd divisor count check