What are the divisors of 230?

1, 2, 5, 10, 23, 46, 115, 230

There is a total of 8 positive divisors.
The sum of these divisors is 432.
The arithmetic mean is 54.

4 even divisors

2, 10, 46, 230

4 odd divisors

1, 5, 23, 115

How to compute the divisors of 230?

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 230 by each of the numbers from 1 to 230 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)

230 / 1 = 230 (the remainder is 0, so 1 is a divisor of 230)
230 / 2 = 115 (the remainder is 0, so 2 is a divisor of 230)
230 / 3 = 76.666666666667 (the remainder is 2, so 3 is not a divisor of 230)
...
230 / 229 = 1.0043668122271 (the remainder is 1, so 229 is not a divisor of 230)
230 / 230 = 1 (the remainder is 0, so 230 is a divisor of 230)

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 230 (i.e. 15.165750888103). 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 $\frac{N}{d} = D$ )

230 / 1 = 230 (the remainder is 0, so 1 and 230 are divisors of 230)
230 / 2 = 115 (the remainder is 0, so 2 and 115 are divisors of 230)
230 / 3 = 76.666666666667 (the remainder is 2, so 3 is not a divisor of 230)
...
230 / 14 = 16.428571428571 (the remainder is 6, so 14 is not a divisor of 230)
230 / 15 = 15.333333333333 (the remainder is 5, so 15 is not a divisor of 230)