What are the divisors of 4916?

1, 2, 4, 1229, 2458, 4916

There is a total of 6 positive divisors.
The sum of these divisors is 8610.
The arithmetic mean is 1435.

4 even divisors

2, 4, 2458, 4916

2 odd divisors

1, 1229

How to compute the divisors of 4916?

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 4916 by each of the numbers from 1 to 4916 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)

4916 / 1 = 4916 (the remainder is 0, so 1 is a divisor of 4916)
4916 / 2 = 2458 (the remainder is 0, so 2 is a divisor of 4916)
4916 / 3 = 1638.6666666667 (the remainder is 2, so 3 is not a divisor of 4916)
...
4916 / 4915 = 1.0002034587996 (the remainder is 1, so 4915 is not a divisor of 4916)
4916 / 4916 = 1 (the remainder is 0, so 4916 is a divisor of 4916)

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 4916 (i.e. 70.114192571832). 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 $\frac{N}{d} = D$ )

4916 / 1 = 4916 (the remainder is 0, so 1 and 4916 are divisors of 4916)
4916 / 2 = 2458 (the remainder is 0, so 2 and 2458 are divisors of 4916)
4916 / 3 = 1638.6666666667 (the remainder is 2, so 3 is not a divisor of 4916)
...
4916 / 69 = 71.246376811594 (the remainder is 17, so 69 is not a divisor of 4916)
4916 / 70 = 70.228571428571 (the remainder is 16, so 70 is not a divisor of 4916)