How to find the factors of 100
Test every whole number from 1 up to the square root of 100 (√100 ≈ 10.000). Each number that divides evenly gives you two factors at once: the divisor and the quotient.
- 100 ÷ 1 = 100 — so 1 and 100 are factors
- 100 ÷ 2 = 50 — so 2 and 50 are factors
- 100 ÷ 3 = 33.333 — not a whole number
- 100 ÷ 4 = 25 — so 4 and 25 are factors
- 100 ÷ 5 = 20 — so 5 and 20 are factors
- 100 ÷ 6 = 16.667 — not a whole number
- 100 ÷ 7 = 14.286 — not a whole number
- 100 ÷ 8 = 12.5 — not a whole number
- 100 ÷ 9 = 11.111 — not a whole number
- 100 ÷ 10 = 10 — so 10 and 10 are factors
Collecting both numbers from every successful division gives the complete list: 1, 2, 4, 5, 10, 20, 25, 50 and 100.
Prime factorization of 100
Divide by the smallest prime that fits, and keep going until the quotient is 1:
The primes you divided by give 100 = 2² × 5². From the exponents you can also count the factors without listing them: (2 + 1) × (2 + 1) = 9.
Properties of 100
- 100 is a composite number.
- The sum of all its factors is 217; the sum of its proper factors (excluding 100) is 117, which makes it a abundant number (its proper factors add up to more than itself).
- 100 is a perfect square: 10 × 10. Perfect squares always have an odd number of factors.
- Multiples of 100 include 200, 300, 400, 500 and so on.
Factors vs. multiples
Factors of 100 are the numbers that divide into it; multiples of 100 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 100?
The factors of 100 are 1, 2, 4, 5, 10, 20, 25, 50 and 100. Each of these divides 100 with no remainder.
How many factors does 100 have?
100 has 9 positive factors, which form 5 factor pairs. Counting negative factors as well doubles that to 18.
What is the prime factorization of 100?
100 = 2² × 5². Its distinct prime factors are 2 and 5.
Is 100 a prime number?
No. 100 is composite because it has 9 factors, more than the two a prime number has.