What are the divisors of 5657?

1, 5657

There is a total of 2 positive divisors.
The sum of these divisors is 5658.
The arithmetic mean is 2829.

2 odd divisors

1, 5657

How to compute the divisors of 5657?

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 5657 by each of the numbers from 1 to 5657 to determine which ones have a remainder equal to 0.

$Remainder = N - (M \times ⌊ \frac{N}{M} ⌋)$

(where $⌊ \frac{N}{M} ⌋$ is the integer part of the quotient)

5657 / 1 = 5657 (the remainder is 0, so 1 is a divisor of 5657)
5657 / 2 = 2828.5 (the remainder is 1, so 2 is not a divisor of 5657)
5657 / 3 = 1885.6666666667 (the remainder is 2, so 3 is not a divisor of 5657)
...
5657 / 5656 = 1.0001768033946 (the remainder is 1, so 5656 is not a divisor of 5657)
5657 / 5657 = 1 (the remainder is 0, so 5657 is a divisor of 5657)

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 5657 (i.e. 75.213030785895). Indeed, if a number N has a divisor D greater than its square root, then there is necessarily a smaller divisor d such that:

$D \times d = N$

(thus, if $\frac{N}{D} = d$ , then $\frac{N}{d} = D$ )

5657 / 1 = 5657 (the remainder is 0, so 1 and 5657 are divisors of 5657)
5657 / 2 = 2828.5 (the remainder is 1, so 2 is not a divisor of 5657)
5657 / 3 = 1885.6666666667 (the remainder is 2, so 3 is not a divisor of 5657)
...
5657 / 74 = 76.445945945946 (the remainder is 33, so 74 is not a divisor of 5657)
5657 / 75 = 75.426666666667 (the remainder is 32, so 75 is not a divisor of 5657)