What are the divisors of 4781?

1, 7, 683, 4781

There is a total of 4 positive divisors.
The sum of these divisors is 5472.
The arithmetic mean is 1368.

4 odd divisors

1, 7, 683, 4781

How to compute the divisors of 4781?

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 4781 by each of the numbers from 1 to 4781 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)

4781 / 1 = 4781 (the remainder is 0, so 1 is a divisor of 4781)
4781 / 2 = 2390.5 (the remainder is 1, so 2 is not a divisor of 4781)
4781 / 3 = 1593.6666666667 (the remainder is 2, so 3 is not a divisor of 4781)
...
4781 / 4780 = 1.0002092050209 (the remainder is 1, so 4780 is not a divisor of 4781)
4781 / 4781 = 1 (the remainder is 0, so 4781 is a divisor of 4781)

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 4781 (i.e. 69.14477565225). 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 $\frac{N}{d} = D$ )

4781 / 1 = 4781 (the remainder is 0, so 1 and 4781 are divisors of 4781)
4781 / 2 = 2390.5 (the remainder is 1, so 2 is not a divisor of 4781)
4781 / 3 = 1593.6666666667 (the remainder is 2, so 3 is not a divisor of 4781)
...
4781 / 68 = 70.308823529412 (the remainder is 21, so 68 is not a divisor of 4781)
4781 / 69 = 69.289855072464 (the remainder is 20, so 69 is not a divisor of 4781)