Factor Calculator

Factors of 42

The factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42. In total, 42 has 8 factors. Its prime factorization is 2 × 3 × 7, and the sum of all its factors is 96.

All factors of 42

Here are all 8 factors of 42, listed from smallest to largest.

12367142142

Factor pairs of 42

These 4 pairs of whole numbers each multiply to give 42.

1 × 42 = 42
2 × 21 = 42
3 × 14 = 42
6 × 7 = 42

Prime factorization of 42

Dividing 42 by the smallest prime at each step gives its prime factorization:

42 ÷ 2 = 21
21 ÷ 3 = 7
7 ÷ 7 = 1
Result: 42 = 2 × 3 × 7 = 2 × 3 × 7

The distinct prime factors of 42 are 2, 3, 7. To factorize any other number, use the prime factorization calculator.

Factor tree of 42

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

Factor tree of 424222137
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 42

Number of factors8
Sum of factors96
Sum of proper factors54
Prime factorization2 × 3 × 7
Prime or composite?Composite
Even or odd?Even
Perfect square?No
Perfect cube?No
ClassificationAbundant

What makes 42 interesting

  • 42 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 4 different ways.
  • 42 is an abundant number: its proper factors sum to 54, which is 12 more than 42 itself.
  • 42 has 3 distinct prime factors (2, 3, 7), which is why it has so many divisors.

How to find the factors of 42 yourself

Divide 42 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 √42 ≈ 6.48, because every factor above that pairs with one below it.

42 ÷ 1 = 42 ✓
42 ÷ 2 = 21 ✓
42 ÷ 3 = 14 ✓
42 ÷ 6 = 7 ✓

Reading both columns gives every factor: 1, 2, 3, 6, 7, 14, 21, 42. The factor calculator does this automatically for any number.

Numbers mathematically connected to 42.

Frequently asked questions about 42

What are the factors of 42?

The factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42. That is 8 factors in total, counting both 1 and 42.

Is 42 a prime number?

No, 42 is not prime — it is a composite number with 8 factors. A prime number has exactly two factors, but 42 is also divisible by 2.

What is the prime factorization of 42?

The prime factorization of 42 is 2 × 3 × 7. Written out in full: 2 × 3 × 7 = 42. Its distinct prime factors are 2, 3, 7.

What two numbers multiply to give 42?

There are 4 pairs of whole numbers that multiply to 42: 1 × 42, 2 × 21, 3 × 14, 6 × 7.

What is the sum of the factors of 42?

Adding all the factors of 42 together gives 96. Excluding 42 itself, the proper factors sum to 54.

Is 42 a perfect square?

No, 42 is not a perfect square. There is no whole number that multiplies by itself to give 42. The nearest perfect squares are 36 and 49.

What is the largest factor of 42 other than itself?

The largest factor of 42 apart from 42 itself is 21, since 42 ÷ 21 = 2.

How many factors does 42 have?

42 has 8 factors: 1, 2, 3, 6, 7, 14, 21, and 42. You can verify this from the prime factorization 2 × 3 × 7: add 1 to each exponent and multiply, giving 2 × 2 × 2 = 8.

Explore more

Try another number in the factor calculator, break 42 down further with the prime factorization calculator, or compare 42 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.