Factor Calculator

Factors of 393

The factors of 393 are 1, 3, 131, and 393. In total, 393 has 4 factors. Its prime factorization is 3 × 131, and the sum of all its factors is 528.

All factors of 393

Here are all 4 factors of 393, listed from smallest to largest.

13131393

Factor pairs of 393

These 2 pairs of whole numbers each multiply to give 393.

1 × 393 = 393
3 × 131 = 393

Prime factorization of 393

Dividing 393 by the smallest prime at each step gives its prime factorization:

393 ÷ 3 = 131
131 ÷ 131 = 1
Result: 393 = 3 × 131 = 3 × 131

The distinct prime factors of 393 are 3, 131. To factorize any other number, use the prime factorization calculator.

Factor tree of 393

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

Factor tree of 3933933131
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 393

Number of factors4
Sum of factors528
Sum of proper factors135
Prime factorization3 × 131
Prime or composite?Composite
Even or odd?Odd
Perfect square?No
Perfect cube?No
ClassificationDeficient

What makes 393 interesting

  • 393 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 2 different ways.
  • 393 is a deficient number: its proper factors sum to 135, which is 258 less than 393 itself.

How to find the factors of 393 yourself

Divide 393 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 √393 ≈ 19.82, because every factor above that pairs with one below it.

393 ÷ 1 = 393 ✓
393 ÷ 3 = 131 ✓

Reading both columns gives every factor: 1, 3, 131, 393. The factor calculator does this automatically for any number.

Numbers mathematically connected to 393.

Frequently asked questions about 393

What are the factors of 393?

The factors of 393 are 1, 3, 131, and 393. That is 4 factors in total, counting both 1 and 393.

Is 393 a prime number?

No, 393 is not prime — it is a composite number with 4 factors. A prime number has exactly two factors, but 393 is also divisible by 3.

What is the prime factorization of 393?

The prime factorization of 393 is 3 × 131. Written out in full: 3 × 131 = 393. Its distinct prime factors are 3, 131.

What two numbers multiply to give 393?

There are 2 pairs of whole numbers that multiply to 393: 1 × 393, 3 × 131.

What is the sum of the factors of 393?

Adding all the factors of 393 together gives 528. Excluding 393 itself, the proper factors sum to 135.

Is 393 a perfect square?

No, 393 is not a perfect square. There is no whole number that multiplies by itself to give 393. The nearest perfect squares are 361 and 400.

What is the largest factor of 393 other than itself?

The largest factor of 393 apart from 393 itself is 131, since 393 ÷ 131 = 3.

How many factors does 393 have?

393 has 4 factors: 1, 3, 131, and 393. You can verify this from the prime factorization 3 × 131: add 1 to each exponent and multiply, giving 2 × 2 = 4.

Explore more

Try another number in the factor calculator, break 393 down further with the prime factorization calculator, or compare 393 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.