What are the divisors of 5501?

1, 5501

There is a total of 2 positive divisors.
The sum of these divisors is 5502.
The arithmetic mean is 2751.

2 odd divisors

1, 5501

How to compute the divisors of 5501?

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 5501 by each of the numbers from 1 to 5501 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)

5501 / 1 = 5501 (the remainder is 0, so 1 is a divisor of 5501)
5501 / 2 = 2750.5 (the remainder is 1, so 2 is not a divisor of 5501)
5501 / 3 = 1833.6666666667 (the remainder is 2, so 3 is not a divisor of 5501)
...
5501 / 5500 = 1.0001818181818 (the remainder is 1, so 5500 is not a divisor of 5501)
5501 / 5501 = 1 (the remainder is 0, so 5501 is a divisor of 5501)

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 5501 (i.e. 74.168726563155). 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 $\frac{N}{d} = D$ )

5501 / 1 = 5501 (the remainder is 0, so 1 and 5501 are divisors of 5501)
5501 / 2 = 2750.5 (the remainder is 1, so 2 is not a divisor of 5501)
5501 / 3 = 1833.6666666667 (the remainder is 2, so 3 is not a divisor of 5501)
...
5501 / 73 = 75.356164383562 (the remainder is 26, so 73 is not a divisor of 5501)
5501 / 74 = 74.337837837838 (the remainder is 25, so 74 is not a divisor of 5501)