Factors of 765

765 has 12 factors: 1, 3, 5, 9, 15, 17, 45, 51, 85, 153, 255 and 765. Its prime factorization is 3² × 5 × 17.

Factor pairs of 765

Factor×FactorProduct
1×765765
3×255765
5×153765
9×85765
15×51765
17×45765

Negative pairs work too: (−1) × (−765), (−3) × (−255), … = 765.

Number of factors
12
Factor pairs
6
Sum of factors
1,404
Prime or composite
Composite
Even or odd
Odd
Perfect square
No
Prime factorization 3² × 5 × 17

How to find the factors of 765

Test every whole number from 1 up to the square root of 765 (√765 ≈ 27.659). Each number that divides evenly gives you two factors at once: the divisor and the quotient.

  • 765 ÷ 1 = 765 — so 1 and 765 are factors
  • 765 ÷ 2 = 382.5 — not a whole number
  • 765 ÷ 3 = 255 — so 3 and 255 are factors
  • 765 ÷ 4 = 191.25 — not a whole number
  • 765 ÷ 5 = 153 — so 5 and 153 are factors
  • 765 ÷ 6 = 127.5 — not a whole number
  • 765 ÷ 7 = 109.286 — not a whole number
  • 765 ÷ 8 = 95.625 — not a whole number
  • 765 ÷ 9 = 85 — so 9 and 85 are factors
  • 765 ÷ 10 = 76.5 — not a whole number
  • 765 ÷ 11 = 69.545 — not a whole number
  • 765 ÷ 12 = 63.75 — not a whole number
  • 765 ÷ 13 = 58.846 — not a whole number
  • 765 ÷ 14 = 54.643 — not a whole number
  • 765 ÷ 15 = 51 — so 15 and 51 are factors
  • 765 ÷ 16 = 47.813 — not a whole number
  • 765 ÷ 17 = 45 — so 17 and 45 are factors
  • 765 ÷ 18 = 42.5 — not a whole number
  • 765 ÷ 19 = 40.263 — not a whole number
  • 765 ÷ 20 = 38.25 — not a whole number
  • 765 ÷ 21 = 36.429 — not a whole number
  • 765 ÷ 22 = 34.773 — not a whole number
  • 765 ÷ 23 = 33.261 — not a whole number
  • 765 ÷ 24 = 31.875 — not a whole number
  • 765 ÷ 25 = 30.6 — not a whole number
  • 765 ÷ 26 = 29.423 — not a whole number
  • 765 ÷ 27 = 28.333 — not a whole number

Collecting both numbers from every successful division gives the complete list: 1, 3, 5, 9, 15, 17, 45, 51, 85, 153, 255 and 765.

Prime factorization of 765

Divide by the smallest prime that fits, and keep going until the quotient is 1:

765 ÷ 3 = 255
255 ÷ 3 = 85
85 ÷ 5 = 17
17 ÷ 17 = 1

The primes you divided by give 765 = 3² × 5 × 17. From the exponents you can also count the factors without listing them: (2 + 1) × (1 + 1) × (1 + 1) = 12.

Properties of 765

  • 765 is a composite number.
  • The sum of all its factors is 1,404; the sum of its proper factors (excluding 765) is 639, which makes it a deficient number (its proper factors add up to less than itself).
  • 765 is not a perfect square, so its factors pair up evenly.
  • Multiples of 765 include 1,530, 2,295, 3,060, 3,825 and so on.

Factors vs. multiples

Factors of 765 are the numbers that divide into it; multiples of 765 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 765?

The factors of 765 are 1, 3, 5, 9, 15, 17, 45, 51, 85, 153, 255 and 765. Each of these divides 765 with no remainder.

How many factors does 765 have?

765 has 12 positive factors, which form 6 factor pairs. Counting negative factors as well doubles that to 24.

What is the prime factorization of 765?

765 = 3² × 5 × 17. Its distinct prime factors are 3, 5 and 17.

Is 765 a prime number?

No. 765 is composite because it has 12 factors, more than the two a prime number has.