What are the divisors of 3103?

1, 29, 107, 3103

There is a total of 4 positive divisors.
The sum of these divisors is 3240.
The arithmetic mean is 810.

4 odd divisors

1, 29, 107, 3103

How to compute the divisors of 3103?

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 3103 by each of the numbers from 1 to 3103 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)

3103 / 1 = 3103 (the remainder is 0, so 1 is a divisor of 3103)
3103 / 2 = 1551.5 (the remainder is 1, so 2 is not a divisor of 3103)
3103 / 3 = 1034.3333333333 (the remainder is 1, so 3 is not a divisor of 3103)
...
3103 / 3102 = 1.0003223726628 (the remainder is 1, so 3102 is not a divisor of 3103)
3103 / 3103 = 1 (the remainder is 0, so 3103 is a divisor of 3103)

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 3103 (i.e. 55.704577908822). 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 $\frac{N}{d} = D$ )

3103 / 1 = 3103 (the remainder is 0, so 1 and 3103 are divisors of 3103)
3103 / 2 = 1551.5 (the remainder is 1, so 2 is not a divisor of 3103)
3103 / 3 = 1034.3333333333 (the remainder is 1, so 3 is not a divisor of 3103)
...
3103 / 54 = 57.462962962963 (the remainder is 25, so 54 is not a divisor of 3103)
3103 / 55 = 56.418181818182 (the remainder is 23, so 55 is not a divisor of 3103)