How to find the factors of 42
Test every whole number from 1 up to the square root of 42 (√42 ≈ 6.481). Each number that divides evenly gives you two factors at once: the divisor and the quotient.
- 42 ÷ 1 = 42 — so 1 and 42 are factors
- 42 ÷ 2 = 21 — so 2 and 21 are factors
- 42 ÷ 3 = 14 — so 3 and 14 are factors
- 42 ÷ 4 = 10.5 — not a whole number
- 42 ÷ 5 = 8.4 — not a whole number
- 42 ÷ 6 = 7 — so 6 and 7 are factors
Collecting both numbers from every successful division gives the complete list: 1, 2, 3, 6, 7, 14, 21 and 42.
Prime factorization of 42
Divide by the smallest prime that fits, and keep going until the quotient is 1:
The primes you divided by give 42 = 2 × 3 × 7. From the exponents you can also count the factors without listing them: (1 + 1) × (1 + 1) × (1 + 1) = 8.
Properties of 42
- 42 is a composite number.
- The sum of all its factors is 96; the sum of its proper factors (excluding 42) is 54, which makes it a abundant number (its proper factors add up to more than itself).
- 42 is not a perfect square, so its factors pair up evenly.
- Multiples of 42 include 84, 126, 168, 210 and so on.
Factors vs. multiples
Factors of 42 are the numbers that divide into it; multiples of 42 are the numbers it divides into. Every number has a limited set of factors but infinitely many multiples. To work with any other number, use the factors calculator, or find shared factors with the GCF calculator.
Frequently asked questions
What are the factors of 42?
The factors of 42 are 1, 2, 3, 6, 7, 14, 21 and 42. Each of these divides 42 with no remainder.
How many factors does 42 have?
42 has 8 positive factors, which form 4 factor pairs. Counting negative factors as well doubles that to 16.
What is the prime factorization of 42?
42 = 2 × 3 × 7. Its distinct prime factors are 2, 3 and 7.
Is 42 a prime number?
No. 42 is composite because it has 8 factors, more than the two a prime number has.