Factor Calculator

Factors of 660

The factors of 660 are 1, 2, 3, 4, 5, 6, 10, 11, 12, 15, 20, 22, 30, 33, 44, 55, 60, 66, 110, 132, 165, 220, 330, and 660. In total, 660 has 24 factors. Its prime factorization is 2² × 3 × 5 × 11, and the sum of all its factors is 2016.

All factors of 660

Here are all 24 factors of 660, listed from smallest to largest.

123456101112152022303344556066110132165220330660

Factor pairs of 660

These 12 pairs of whole numbers each multiply to give 660.

1 × 660 = 660
2 × 330 = 660
3 × 220 = 660
4 × 165 = 660
5 × 132 = 660
6 × 110 = 660
10 × 66 = 660
11 × 60 = 660
12 × 55 = 660
15 × 44 = 660
20 × 33 = 660
22 × 30 = 660

Prime factorization of 660

Dividing 660 by the smallest prime at each step gives its prime factorization:

660 ÷ 2 = 330
330 ÷ 2 = 165
165 ÷ 3 = 55
55 ÷ 5 = 11
11 ÷ 11 = 1
Result: 660 = 2 × 2 × 3 × 5 × 11 = 2² × 3 × 5 × 11

The distinct prime factors of 660 are 2, 3, 5, 11. To factorize any other number, use the prime factorization calculator.

Factor tree of 660

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

Factor tree of 66066023302165355511
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 660

Number of factors24
Sum of factors2016
Sum of proper factors1356
Prime factorization2² × 3 × 5 × 11
Prime or composite?Composite
Even or odd?Even
Perfect square?No
Perfect cube?No
ClassificationAbundant

What makes 660 interesting

  • 660 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 12 different ways.
  • 660 is an abundant number: its proper factors sum to 1356, which is 696 more than 660 itself.
  • 660 has 4 distinct prime factors (2, 3, 5, 11), which is why it has so many divisors.

How to find the factors of 660 yourself

Divide 660 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 √660 ≈ 25.69, because every factor above that pairs with one below it.

660 ÷ 1 = 660 ✓
660 ÷ 2 = 330 ✓
660 ÷ 3 = 220 ✓
660 ÷ 4 = 165 ✓
660 ÷ 5 = 132 ✓
660 ÷ 6 = 110 ✓
660 ÷ 10 = 66 ✓
660 ÷ 11 = 60 ✓
660 ÷ 12 = 55 ✓
660 ÷ 15 = 44 ✓
660 ÷ 20 = 33 ✓
660 ÷ 22 = 30 ✓

Reading both columns gives every factor: 1, 2, 3, 4, 5, 6, 10, 11, 12, 15, 20, 22, 30, 33, 44, 55, 60, 66, 110, 132, 165, 220, 330, 660. The factor calculator does this automatically for any number.

Numbers mathematically connected to 660.

Frequently asked questions about 660

What are the factors of 660?

The factors of 660 are 1, 2, 3, 4, 5, 6, 10, 11, 12, 15, 20, 22, 30, 33, 44, 55, 60, 66, 110, 132, 165, 220, 330, and 660. That is 24 factors in total, counting both 1 and 660.

Is 660 a prime number?

No, 660 is not prime — it is a composite number with 24 factors. A prime number has exactly two factors, but 660 is also divisible by 2.

What is the prime factorization of 660?

The prime factorization of 660 is 2² × 3 × 5 × 11. Written out in full: 2 × 2 × 3 × 5 × 11 = 660. Its distinct prime factors are 2, 3, 5, 11.

What two numbers multiply to give 660?

There are 12 pairs of whole numbers that multiply to 660: 1 × 660, 2 × 330, 3 × 220, 4 × 165, 5 × 132, 6 × 110, 10 × 66, 11 × 60, 12 × 55, 15 × 44, 20 × 33, 22 × 30.

What is the sum of the factors of 660?

Adding all the factors of 660 together gives 2016. Excluding 660 itself, the proper factors sum to 1356.

Is 660 a perfect square?

No, 660 is not a perfect square. There is no whole number that multiplies by itself to give 660. The nearest perfect squares are 625 and 676.

What is the largest factor of 660 other than itself?

The largest factor of 660 apart from 660 itself is 330, since 660 ÷ 330 = 2.

How many factors does 660 have?

660 has 24 factors: 1, 2, 3, 4, 5, 6, 10, 11, 12, 15, 20, 22, 30, 33, 44, 55, 60, 66, 110, 132, 165, 220, 330, and 660. You can verify this from the prime factorization 2² × 3 × 5 × 11: add 1 to each exponent and multiply, giving 3 × 2 × 2 × 2 = 24.

Explore more

Try another number in the factor calculator, break 660 down further with the prime factorization calculator, or compare 660 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.