What are the divisors of 5393?

1, 5393

There is a total of 2 positive divisors.
The sum of these divisors is 5394.
The arithmetic mean is 2697.

2 odd divisors

1, 5393

How to compute the divisors of 5393?

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 5393 by each of the numbers from 1 to 5393 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)

5393 / 1 = 5393 (the remainder is 0, so 1 is a divisor of 5393)
5393 / 2 = 2696.5 (the remainder is 1, so 2 is not a divisor of 5393)
5393 / 3 = 1797.6666666667 (the remainder is 2, so 3 is not a divisor of 5393)
...
5393 / 5392 = 1.0001854599407 (the remainder is 1, so 5392 is not a divisor of 5393)
5393 / 5393 = 1 (the remainder is 0, so 5393 is a divisor of 5393)

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 5393 (i.e. 73.437047870949). 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 $\frac{N}{d} = D$ )

5393 / 1 = 5393 (the remainder is 0, so 1 and 5393 are divisors of 5393)
5393 / 2 = 2696.5 (the remainder is 1, so 2 is not a divisor of 5393)
5393 / 3 = 1797.6666666667 (the remainder is 2, so 3 is not a divisor of 5393)
...
5393 / 72 = 74.902777777778 (the remainder is 65, so 72 is not a divisor of 5393)
5393 / 73 = 73.876712328767 (the remainder is 64, so 73 is not a divisor of 5393)