Divisors of 16821: All 16 Factors
Quick Answer
16821 has 16 divisors (factors): 1, 3, 7, 9, 21, 27, 63, 89, 189, 267, 623, 801, 1869, 2403, 5607, 16821.
Sum: 28800.
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 16821
The number 16821 has 16 divisors:
1, 3, 7, 9, 21, 27, 63, 89, 189, 267, 623, 801, 1869, 2403, 5607, 16821
Divisor Pairs of 16821
Each pair multiplies to 16821:
| Factor 1 | × | Factor 2 | = | Product |
|---|---|---|---|---|
| 1 | × | 16821 | = | 16821 |
| 3 | × | 5607 | = | 16821 |
| 7 | × | 2403 | = | 16821 |
| 9 | × | 1869 | = | 16821 |
| 21 | × | 801 | = | 16821 |
| 27 | × | 623 | = | 16821 |
| 63 | × | 267 | = | 16821 |
| 89 | × | 189 | = | 16821 |
Number of Divisors
The number 16821 has 16 divisors, written as τ(16821) = 16 in number theory.
Sum of Divisors
σ(16821) = 1 + 3 + 7 + 9 + 21 + 27 + 63 + 89 + 189 + 267 + 623 + 801 + 1869 + 2403 + 5607 + 16821 = 28800
Prime Factorization of 16821
Properties of 16821
- 16821 is composite.
- 16821 is not a perfect square.
- Number of divisors: 16.
- Sum of divisors: 28800.
Common Divisors with Another Number?
Looking for the divisors that 16821 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 16821
An efficient way to find divisors uses the complementary pair trick: check each integer i from 1 to √16821 ≈ 129.70. If i divides 16821, then both i and 16821/i are divisors.
- 1 divides 16821 (16821 ÷ 1 = 16821) → pair (1, 16821)
- 3 divides 16821 (16821 ÷ 3 = 5607) → pair (3, 5607)
- 7 divides 16821 (16821 ÷ 7 = 2403) → pair (7, 2403)
- 9 divides 16821 (16821 ÷ 9 = 1869) → pair (9, 1869)
- 21 divides 16821 (16821 ÷ 21 = 801) → pair (21, 801)
- 27 divides 16821 (16821 ÷ 27 = 623) → pair (27, 623)
- 63 divides 16821 (16821 ÷ 63 = 267) → pair (63, 267)
- 89 divides 16821 (16821 ÷ 89 = 189) → pair (89, 189)
- Collect all unique values: {1, 3, 7, 9, 21, 27, 63, 89, 189, 267, 623, 801, 1869, 2403, 5607, 16821} — total 16 divisors.
- Sum: 1 + 3 + 7 + 9 + 21 + 27 + 63 + 89 + 189 + 267 + 623 + 801 + 1869 + 2403 + 5607 + 16821 = 28800.
Nearby Examples
Related Operations for 16821
- Multiples of a Number — "outward" complement of divisors
- 16821 Prime Factorization — decompose into prime building blocks
- Find GCF of 16821 and another number
- Find LCM of 16821 and another number
- Is 16821 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