What are the divisors of 2281?

1, 2281

There is a total of 2 positive divisors.
The sum of these divisors is 2282.
The arithmetic mean is 1141.

2 odd divisors

1, 2281

How to compute the divisors of 2281?

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 2281 by each of the numbers from 1 to 2281 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)

2281 / 1 = 2281 (the remainder is 0, so 1 is a divisor of 2281)
2281 / 2 = 1140.5 (the remainder is 1, so 2 is not a divisor of 2281)
2281 / 3 = 760.33333333333 (the remainder is 1, so 3 is not a divisor of 2281)
...
2281 / 2280 = 1.0004385964912 (the remainder is 1, so 2280 is not a divisor of 2281)
2281 / 2281 = 1 (the remainder is 0, so 2281 is a divisor of 2281)

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 2281 (i.e. 47.759815745038). 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 $\frac{N}{d} = D$ )

2281 / 1 = 2281 (the remainder is 0, so 1 and 2281 are divisors of 2281)
2281 / 2 = 1140.5 (the remainder is 1, so 2 is not a divisor of 2281)
2281 / 3 = 760.33333333333 (the remainder is 1, so 3 is not a divisor of 2281)
...
2281 / 46 = 49.586956521739 (the remainder is 27, so 46 is not a divisor of 2281)
2281 / 47 = 48.531914893617 (the remainder is 25, so 47 is not a divisor of 2281)