What are the divisors of 9017?

1, 71, 127, 9017

There is a total of 4 positive divisors.
The sum of these divisors is 9216.
The arithmetic mean is 2304.

4 odd divisors

1, 71, 127, 9017

How to compute the divisors of 9017?

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 9017 by each of the numbers from 1 to 9017 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)

9017 / 1 = 9017 (the remainder is 0, so 1 is a divisor of 9017)
9017 / 2 = 4508.5 (the remainder is 1, so 2 is not a divisor of 9017)
9017 / 3 = 3005.6666666667 (the remainder is 2, so 3 is not a divisor of 9017)
...
9017 / 9016 = 1.0001109139308 (the remainder is 1, so 9016 is not a divisor of 9017)
9017 / 9017 = 1 (the remainder is 0, so 9017 is a divisor of 9017)

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 9017 (i.e. 94.957885401898). 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 $\frac{N}{d} = D$ )

9017 / 1 = 9017 (the remainder is 0, so 1 and 9017 are divisors of 9017)
9017 / 2 = 4508.5 (the remainder is 1, so 2 is not a divisor of 9017)
9017 / 3 = 3005.6666666667 (the remainder is 2, so 3 is not a divisor of 9017)
...
9017 / 93 = 96.956989247312 (the remainder is 89, so 93 is not a divisor of 9017)
9017 / 94 = 95.925531914894 (the remainder is 87, so 94 is not a divisor of 9017)