Factor Calculator

Factors of 315

The factors of 315 are 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105, and 315. In total, 315 has 12 factors. Its prime factorization is 3² × 5 × 7, and the sum of all its factors is 624.

All factors of 315

Here are all 12 factors of 315, listed from smallest to largest.

135791521354563105315

Factor pairs of 315

These 6 pairs of whole numbers each multiply to give 315.

1 × 315 = 315
3 × 105 = 315
5 × 63 = 315
7 × 45 = 315
9 × 35 = 315
15 × 21 = 315

Prime factorization of 315

Dividing 315 by the smallest prime at each step gives its prime factorization:

315 ÷ 3 = 105
105 ÷ 3 = 35
35 ÷ 5 = 7
7 ÷ 7 = 1
Result: 315 = 3 × 3 × 5 × 7 = 3² × 5 × 7

The distinct prime factors of 315 are 3, 5, 7. To factorize any other number, use the prime factorization calculator.

Factor tree of 315

A factor tree shows the same prime factorization visually. Each composite branch splits until every endpoint is a prime number.

Factor tree of 315315310533557
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 315

Number of factors12
Sum of factors624
Sum of proper factors309
Prime factorization3² × 5 × 7
Prime or composite?Composite
Even or odd?Odd
Perfect square?No
Perfect cube?No
ClassificationDeficient

What makes 315 interesting

  • 315 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 6 different ways.
  • 315 is a deficient number: its proper factors sum to 309, which is 6 less than 315 itself.
  • 315 has 3 distinct prime factors (3, 5, 7), which is why it has so many divisors.

How to find the factors of 315 yourself

Divide 315 by each whole number starting from 1. Whenever the division leaves no remainder, both the divisor and the quotient are factors. You only need to test up to √31517.75, because every factor above that pairs with one below it.

315 ÷ 1 = 315
315 ÷ 3 = 105
315 ÷ 5 = 63
315 ÷ 7 = 45
315 ÷ 9 = 35
315 ÷ 15 = 21

Reading both columns gives every factor: 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105, 315. The factor calculator does this automatically for any number.

Frequently asked questions about 315

What are the factors of 315?

The factors of 315 are 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105, and 315. That is 12 factors in total, counting both 1 and 315.

Is 315 a prime number?

No, 315 is not prime — it is a composite number with 12 factors. A prime number has exactly two factors, but 315 is also divisible by 3.

What is the prime factorization of 315?

The prime factorization of 315 is 3² × 5 × 7. Written out in full: 3 × 3 × 5 × 7 = 315. Its distinct prime factors are 3, 5, 7.

What two numbers multiply to give 315?

There are 6 pairs of whole numbers that multiply to 315: 1 × 315, 3 × 105, 5 × 63, 7 × 45, 9 × 35, 15 × 21.

What is the sum of the factors of 315?

Adding all the factors of 315 together gives 624. Excluding 315 itself, the proper factors sum to 309.

Is 315 a perfect square?

No, 315 is not a perfect square. There is no whole number that multiplies by itself to give 315. The nearest perfect squares are 289 and 324.

What is the largest factor of 315 other than itself?

The largest factor of 315 apart from 315 itself is 105, since 315 ÷ 105 = 3.

How many factors does 315 have?

315 has 12 factors: 1, 3, 5, 7, 9, 15, 21, 35, 45, 63, 105, and 315. You can verify this from the prime factorization 3² × 5 × 7: add 1 to each exponent and multiply, giving 3 × 2 × 2 = 12.

Explore more

Try another number in the factor calculator, break 315 down further with the prime factorization calculator, or compare 315 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.