How to find the factors of 217
Test every whole number from 1 up to the square root of 217 (√217 ≈ 14.731). Each number that divides evenly gives you two factors at once: the divisor and the quotient.
- 217 ÷ 1 = 217 — so 1 and 217 are factors
- 217 ÷ 2 = 108.5 — not a whole number
- 217 ÷ 3 = 72.333 — not a whole number
- 217 ÷ 4 = 54.25 — not a whole number
- 217 ÷ 5 = 43.4 — not a whole number
- 217 ÷ 6 = 36.167 — not a whole number
- 217 ÷ 7 = 31 — so 7 and 31 are factors
- 217 ÷ 8 = 27.125 — not a whole number
- 217 ÷ 9 = 24.111 — not a whole number
- 217 ÷ 10 = 21.7 — not a whole number
- 217 ÷ 11 = 19.727 — not a whole number
- 217 ÷ 12 = 18.083 — not a whole number
- 217 ÷ 13 = 16.692 — not a whole number
- 217 ÷ 14 = 15.5 — not a whole number
Collecting both numbers from every successful division gives the complete list: 1, 7, 31 and 217.
Prime factorization of 217
Divide by the smallest prime that fits, and keep going until the quotient is 1:
The primes you divided by give 217 = 7 × 31. From the exponents you can also count the factors without listing them: (1 + 1) × (1 + 1) = 4.
Properties of 217
- 217 is a composite number.
- The sum of all its factors is 256; the sum of its proper factors (excluding 217) is 39, which makes it a deficient number (its proper factors add up to less than itself).
- 217 is not a perfect square, so its factors pair up evenly.
- Multiples of 217 include 434, 651, 868, 1,085 and so on.
Factors vs. multiples
Factors of 217 are the numbers that divide into it; multiples of 217 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 217?
The factors of 217 are 1, 7, 31 and 217. Each of these divides 217 with no remainder.
How many factors does 217 have?
217 has 4 positive factors, which form 2 factor pairs. Counting negative factors as well doubles that to 8.
What is the prime factorization of 217?
217 = 7 × 31. Its distinct prime factors are 7 and 31.
Is 217 a prime number?
No. 217 is composite because it has 4 factors, more than the two a prime number has.