What are the divisors of 3051?

1, 3, 9, 27, 113, 339, 1017, 3051

8 odd divisors

1, 3, 9, 27, 113, 339, 1017, 3051

How to compute the divisors of 3051?

A number N is said to be divisible by a number M (with M non-zero) if, when we divide N by M, the remainder of the division is zero.

N mod M = 0

Brute force algorithm

We could start by using a brute-force method which would involve dividing 3051 by each of the numbers from 1 to 3051 to determine which ones have a remainder equal to 0.

Remainder = N ( M × N M )

(where N M is the integer part of the quotient)

  • 3051 / 1 = 3051 (the remainder is 0, so 1 is a divisor of 3051)
  • 3051 / 2 = 1525.5 (the remainder is 1, so 2 is not a divisor of 3051)
  • 3051 / 3 = 1017 (the remainder is 0, so 3 is a divisor of 3051)
  • ...
  • 3051 / 3050 = 1.0003278688525 (the remainder is 1, so 3050 is not a divisor of 3051)
  • 3051 / 3051 = 1 (the remainder is 0, so 3051 is a divisor of 3051)

Improved algorithm using square-root

However, there is another slightly better approach that reduces the number of iterations by testing only integers less than or equal to the square root of 3051 (i.e. 55.235857918566). Indeed, if a number N has a divisor D greater than its square root, then there is necessarily a smaller divisor d such that:

D × d = N

(thus, if N D = d , then N d = D )

  • 3051 / 1 = 3051 (the remainder is 0, so 1 and 3051 are divisors of 3051)
  • 3051 / 2 = 1525.5 (the remainder is 1, so 2 is not a divisor of 3051)
  • 3051 / 3 = 1017 (the remainder is 0, so 3 and 1017 are divisors of 3051)
  • ...
  • 3051 / 54 = 56.5 (the remainder is 27, so 54 is not a divisor of 3051)
  • 3051 / 55 = 55.472727272727 (the remainder is 26, so 55 is not a divisor of 3051)