What are the divisors of 5558?

1, 2, 7, 14, 397, 794, 2779, 5558

There is a total of 8 positive divisors.
The sum of these divisors is 9552.
The arithmetic mean is 1194.

4 even divisors

2, 14, 794, 5558

4 odd divisors

1, 7, 397, 2779

How to compute the divisors of 5558?

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 5558 by each of the numbers from 1 to 5558 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)

5558 / 1 = 5558 (the remainder is 0, so 1 is a divisor of 5558)
5558 / 2 = 2779 (the remainder is 0, so 2 is a divisor of 5558)
5558 / 3 = 1852.6666666667 (the remainder is 2, so 3 is not a divisor of 5558)
...
5558 / 5557 = 1.0001799532122 (the remainder is 1, so 5557 is not a divisor of 5558)
5558 / 5558 = 1 (the remainder is 0, so 5558 is a divisor of 5558)

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 5558 (i.e. 74.551995278463). 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 $\frac{N}{d} = D$ )

5558 / 1 = 5558 (the remainder is 0, so 1 and 5558 are divisors of 5558)
5558 / 2 = 2779 (the remainder is 0, so 2 and 2779 are divisors of 5558)
5558 / 3 = 1852.6666666667 (the remainder is 2, so 3 is not a divisor of 5558)
...
5558 / 73 = 76.13698630137 (the remainder is 10, so 73 is not a divisor of 5558)
5558 / 74 = 75.108108108108 (the remainder is 8, so 74 is not a divisor of 5558)