Factor Calculator

Factors of 420

The factors of 420 are 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, 210, and 420. In total, 420 has 24 factors. Its prime factorization is 2² × 3 × 5 × 7, and the sum of all its factors is 1344.

All factors of 420

Here are all 24 factors of 420, listed from smallest to largest.

123456710121415202128303542607084105140210420

Factor pairs of 420

These 12 pairs of whole numbers each multiply to give 420.

1 × 420 = 420
2 × 210 = 420
3 × 140 = 420
4 × 105 = 420
5 × 84 = 420
6 × 70 = 420
7 × 60 = 420
10 × 42 = 420
12 × 35 = 420
14 × 30 = 420
15 × 28 = 420
20 × 21 = 420

Prime factorization of 420

Dividing 420 by the smallest prime at each step gives its prime factorization:

420 ÷ 2 = 210
210 ÷ 2 = 105
105 ÷ 3 = 35
35 ÷ 5 = 7
7 ÷ 7 = 1
Result: 420 = 2 × 2 × 3 × 5 × 7 = 2² × 3 × 5 × 7

The distinct prime factors of 420 are 2, 3, 5, 7. To factorize any other number, use the prime factorization calculator.

Factor tree of 420

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

Factor tree of 4204202210210533557
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 420

Number of factors24
Sum of factors1344
Sum of proper factors924
Prime factorization2² × 3 × 5 × 7
Prime or composite?Composite
Even or odd?Even
Perfect square?No
Perfect cube?No
ClassificationAbundant

What makes 420 interesting

  • 420 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.
  • 420 is an abundant number: its proper factors sum to 924, which is 504 more than 420 itself.
  • 420 has 4 distinct prime factors (2, 3, 5, 7), which is why it has so many divisors.

How to find the factors of 420 yourself

Divide 420 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 √42020.49, because every factor above that pairs with one below it.

420 ÷ 1 = 420
420 ÷ 2 = 210
420 ÷ 3 = 140
420 ÷ 4 = 105
420 ÷ 5 = 84
420 ÷ 6 = 70
420 ÷ 7 = 60
420 ÷ 10 = 42
420 ÷ 12 = 35
420 ÷ 14 = 30
420 ÷ 15 = 28
420 ÷ 20 = 21

Reading both columns gives every factor: 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, 210, 420. The factor calculator does this automatically for any number.

Frequently asked questions about 420

What are the factors of 420?

The factors of 420 are 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, 210, and 420. That is 24 factors in total, counting both 1 and 420.

Is 420 a prime number?

No, 420 is not prime — it is a composite number with 24 factors. A prime number has exactly two factors, but 420 is also divisible by 2.

What is the prime factorization of 420?

The prime factorization of 420 is 2² × 3 × 5 × 7. Written out in full: 2 × 2 × 3 × 5 × 7 = 420. Its distinct prime factors are 2, 3, 5, 7.

What two numbers multiply to give 420?

There are 12 pairs of whole numbers that multiply to 420: 1 × 420, 2 × 210, 3 × 140, 4 × 105, 5 × 84, 6 × 70, 7 × 60, 10 × 42, 12 × 35, 14 × 30, 15 × 28, 20 × 21.

What is the sum of the factors of 420?

Adding all the factors of 420 together gives 1344. Excluding 420 itself, the proper factors sum to 924.

Is 420 a perfect square?

No, 420 is not a perfect square. There is no whole number that multiplies by itself to give 420. The nearest perfect squares are 400 and 441.

What is the largest factor of 420 other than itself?

The largest factor of 420 apart from 420 itself is 210, since 420 ÷ 210 = 2.

How many factors does 420 have?

420 has 24 factors: 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, 210, and 420. You can verify this from the prime factorization 2² × 3 × 5 × 7: add 1 to each exponent and multiply, giving 3 × 2 × 2 × 2 = 24.

Explore more

Try another number in the factor calculator, break 420 down further with the prime factorization calculator, or compare 420 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.