Factor Calculator

Factors of 99

The factors of 99 are 1, 3, 9, 11, 33, and 99. In total, 99 has 6 factors. Its prime factorization is 3² × 11, and the sum of all its factors is 156.

All factors of 99

Here are all 6 factors of 99, listed from smallest to largest.

139113399

Factor pairs of 99

These 3 pairs of whole numbers each multiply to give 99.

1 × 99 = 99
3 × 33 = 99
9 × 11 = 99

Prime factorization of 99

Dividing 99 by the smallest prime at each step gives its prime factorization:

99 ÷ 3 = 33
33 ÷ 3 = 11
11 ÷ 11 = 1
Result: 99 = 3 × 3 × 11 = 3² × 11

The distinct prime factors of 99 are 3, 11. To factorize any other number, use the prime factorization calculator.

Factor tree of 99

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

Factor tree of 9999333311
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 99

Number of factors6
Sum of factors156
Sum of proper factors57
Prime factorization3² × 11
Prime or composite?Composite
Even or odd?Odd
Perfect square?No
Perfect cube?No
ClassificationDeficient

What makes 99 interesting

  • 99 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 3 different ways.
  • 99 is a deficient number: its proper factors sum to 57, which is 42 less than 99 itself.

How to find the factors of 99 yourself

Divide 99 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 √99 ≈ 9.95, because every factor above that pairs with one below it.

99 ÷ 1 = 99 ✓
99 ÷ 3 = 33 ✓
99 ÷ 9 = 11 ✓

Reading both columns gives every factor: 1, 3, 9, 11, 33, 99. The factor calculator does this automatically for any number.

Numbers mathematically connected to 99.

Frequently asked questions about 99

What are the factors of 99?

The factors of 99 are 1, 3, 9, 11, 33, and 99. That is 6 factors in total, counting both 1 and 99.

Is 99 a prime number?

No, 99 is not prime — it is a composite number with 6 factors. A prime number has exactly two factors, but 99 is also divisible by 3.

What is the prime factorization of 99?

The prime factorization of 99 is 3² × 11. Written out in full: 3 × 3 × 11 = 99. Its distinct prime factors are 3, 11.

What two numbers multiply to give 99?

There are 3 pairs of whole numbers that multiply to 99: 1 × 99, 3 × 33, 9 × 11.

What is the sum of the factors of 99?

Adding all the factors of 99 together gives 156. Excluding 99 itself, the proper factors sum to 57.

Is 99 a perfect square?

No, 99 is not a perfect square. There is no whole number that multiplies by itself to give 99. The nearest perfect squares are 81 and 100.

What is the largest factor of 99 other than itself?

The largest factor of 99 apart from 99 itself is 33, since 99 ÷ 33 = 3.

How many factors does 99 have?

99 has 6 factors: 1, 3, 9, 11, 33, and 99. You can verify this from the prime factorization 3² × 11: add 1 to each exponent and multiply, giving 3 × 2 = 6.

Explore more

Try another number in the factor calculator, break 99 down further with the prime factorization calculator, or compare 99 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.