Factors of 315

315 has 12 factors: 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105 and 315. Its prime factorization is 3² × 5 × 7.

Factor pairs of 315

Factor×FactorProduct
1×315315
3×105315
5×63315
7×45315
9×35315
15×21315

Negative pairs work too: (−1) × (−315), (−3) × (−105), … = 315.

Number of factors
12
Factor pairs
6
Sum of factors
624
Prime or composite
Composite
Even or odd
Odd
Perfect square
No
Prime factorization 3² × 5 × 7

How to find the factors of 315

Test every whole number from 1 up to the square root of 315 (√315 ≈ 17.748). Each number that divides evenly gives you two factors at once: the divisor and the quotient.

  • 315 ÷ 1 = 315 — so 1 and 315 are factors
  • 315 ÷ 2 = 157.5 — not a whole number
  • 315 ÷ 3 = 105 — so 3 and 105 are factors
  • 315 ÷ 4 = 78.75 — not a whole number
  • 315 ÷ 5 = 63 — so 5 and 63 are factors
  • 315 ÷ 6 = 52.5 — not a whole number
  • 315 ÷ 7 = 45 — so 7 and 45 are factors
  • 315 ÷ 8 = 39.375 — not a whole number
  • 315 ÷ 9 = 35 — so 9 and 35 are factors
  • 315 ÷ 10 = 31.5 — not a whole number
  • 315 ÷ 11 = 28.636 — not a whole number
  • 315 ÷ 12 = 26.25 — not a whole number
  • 315 ÷ 13 = 24.231 — not a whole number
  • 315 ÷ 14 = 22.5 — not a whole number
  • 315 ÷ 15 = 21 — so 15 and 21 are factors
  • 315 ÷ 16 = 19.688 — not a whole number
  • 315 ÷ 17 = 18.529 — not a whole number

Collecting both numbers from every successful division gives the complete list: 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105 and 315.

Prime factorization of 315

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

315 ÷ 3 = 105
105 ÷ 3 = 35
35 ÷ 5 = 7
7 ÷ 7 = 1

The primes you divided by give 315 = 3² × 5 × 7. From the exponents you can also count the factors without listing them: (2 + 1) × (1 + 1) × (1 + 1) = 12.

Properties of 315

  • 315 is a composite number.
  • The sum of all its factors is 624; the sum of its proper factors (excluding 315) is 309, which makes it a deficient number (its proper factors add up to less than itself).
  • 315 is not a perfect square, so its factors pair up evenly.
  • Multiples of 315 include 630, 945, 1,260, 1,575 and so on.

Factors vs. multiples

Factors of 315 are the numbers that divide into it; multiples of 315 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 315?

The factors of 315 are 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105 and 315. Each of these divides 315 with no remainder.

How many factors does 315 have?

315 has 12 positive factors, which form 6 factor pairs. Counting negative factors as well doubles that to 24.

What is the prime factorization of 315?

315 = 3² × 5 × 7. Its distinct prime factors are 3, 5 and 7.

Is 315 a prime number?

No. 315 is composite because it has 12 factors, more than the two a prime number has.