Divisors of 243: All 6 Factors

Quick Answer

243 has 6 divisors (factors): 1, 3, 9, 27, 81, 243.

Sum: 364.

Divisors (Factors) Calculator


  Ex.: 12, 36, 100, 1024, 1728, etc.
6 divisors
1, 3, 9, 27, 81, 243

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 243

The number 243 has 6 divisors:

1,  3,  9,  27,  81,  243

Divisor Pairs of 243

Each pair multiplies to 243:

Factor 1×Factor 2=Product
1×243=243
3×81=243
9×27=243

Number of Divisors

The number 243 has 6 divisors, written as τ(243) = 6 in number theory.

Sum of Divisors

σ(243) = 1 + 3 + 9 + 27 + 81 + 243 = 364

Properties of 243

  • 243 is composite.
  • 243 is not a perfect square.
  • Number of divisors: 6.
  • Sum of divisors: 364.

Common Divisors with Another Number?

Looking for the divisors that 243 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 243

An efficient way to find divisors uses the complementary pair trick: check each integer i from 1 to √243 ≈ 15.59. If i divides 243, then both i and 243/i are divisors.

  1. 1 divides 243 (243 ÷ 1 = 243) → pair (1, 243)
  2. 3 divides 243 (243 ÷ 3 = 81) → pair (3, 81)
  3. 9 divides 243 (243 ÷ 9 = 27) → pair (9, 27)
  4. Collect all unique values: {1, 3, 9, 27, 81, 243} — total 6 divisors.
  5. Sum: 1 + 3 + 9 + 27 + 81 + 243 = 364.

Nearby Examples

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Related Operations for 243

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.

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