What are the divisors of 2533?

1, 17, 149, 2533

4 odd divisors

1, 17, 149, 2533

How to compute the divisors of 2533?

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 2533 by each of the numbers from 1 to 2533 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)

  • 2533 / 1 = 2533 (the remainder is 0, so 1 is a divisor of 2533)
  • 2533 / 2 = 1266.5 (the remainder is 1, so 2 is not a divisor of 2533)
  • 2533 / 3 = 844.33333333333 (the remainder is 1, so 3 is not a divisor of 2533)
  • ...
  • 2533 / 2532 = 1.0003949447077 (the remainder is 1, so 2532 is not a divisor of 2533)
  • 2533 / 2533 = 1 (the remainder is 0, so 2533 is a divisor of 2533)

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 2533 (i.e. 50.328918128646). 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 )

  • 2533 / 1 = 2533 (the remainder is 0, so 1 and 2533 are divisors of 2533)
  • 2533 / 2 = 1266.5 (the remainder is 1, so 2 is not a divisor of 2533)
  • 2533 / 3 = 844.33333333333 (the remainder is 1, so 3 is not a divisor of 2533)
  • ...
  • 2533 / 49 = 51.69387755102 (the remainder is 34, so 49 is not a divisor of 2533)
  • 2533 / 50 = 50.66 (the remainder is 33, so 50 is not a divisor of 2533)