Factors of 225

225 has 9 factors: 1, 3, 5, 9, 15, 25, 45, 75 and 225. Its prime factorization is 3² × 5².

Factor pairs of 225

Factor×FactorProduct
1×225225
3×75225
5×45225
9×25225
15×15225

Negative pairs work too: (−1) × (−225), (−3) × (−75), … = 225.

Number of factors
9
Factor pairs
5
Sum of factors
403
Prime or composite
Composite
Even or odd
Odd
Perfect square
Yes (15²)
Prime factorization 3² × 5²

How to find the factors of 225

Test every whole number from 1 up to the square root of 225 (√225 ≈ 15.000). Each number that divides evenly gives you two factors at once: the divisor and the quotient.

  • 225 ÷ 1 = 225 — so 1 and 225 are factors
  • 225 ÷ 2 = 112.5 — not a whole number
  • 225 ÷ 3 = 75 — so 3 and 75 are factors
  • 225 ÷ 4 = 56.25 — not a whole number
  • 225 ÷ 5 = 45 — so 5 and 45 are factors
  • 225 ÷ 6 = 37.5 — not a whole number
  • 225 ÷ 7 = 32.143 — not a whole number
  • 225 ÷ 8 = 28.125 — not a whole number
  • 225 ÷ 9 = 25 — so 9 and 25 are factors
  • 225 ÷ 10 = 22.5 — not a whole number
  • 225 ÷ 11 = 20.455 — not a whole number
  • 225 ÷ 12 = 18.75 — not a whole number
  • 225 ÷ 13 = 17.308 — not a whole number
  • 225 ÷ 14 = 16.071 — not a whole number
  • 225 ÷ 15 = 15 — so 15 and 15 are factors

Collecting both numbers from every successful division gives the complete list: 1, 3, 5, 9, 15, 25, 45, 75 and 225.

Prime factorization of 225

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

225 ÷ 3 = 75
75 ÷ 3 = 25
25 ÷ 5 = 5
5 ÷ 5 = 1

The primes you divided by give 225 = 3² × 5². From the exponents you can also count the factors without listing them: (2 + 1) × (2 + 1) = 9.

Properties of 225

  • 225 is a composite number.
  • The sum of all its factors is 403; the sum of its proper factors (excluding 225) is 178, which makes it a deficient number (its proper factors add up to less than itself).
  • 225 is a perfect square: 15 × 15. Perfect squares always have an odd number of factors.
  • Multiples of 225 include 450, 675, 900, 1,125 and so on.

Factors vs. multiples

Factors of 225 are the numbers that divide into it; multiples of 225 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.

Frequently asked questions

What are the factors of 225?

The factors of 225 are 1, 3, 5, 9, 15, 25, 45, 75 and 225. Each of these divides 225 with no remainder.

How many factors does 225 have?

225 has 9 positive factors, which form 5 factor pairs. Counting negative factors as well doubles that to 18.

What is the prime factorization of 225?

225 = 3² × 5². Its distinct prime factors are 3 and 5.

Is 225 a prime number?

No. 225 is composite because it has 9 factors, more than the two a prime number has.