What are the divisors of 1303?

1, 1303

There is a total of 2 positive divisors.
The sum of these divisors is 1304.
The arithmetic mean is 652.

2 odd divisors

1, 1303

How to compute the divisors of 1303?

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 1303 by each of the numbers from 1 to 1303 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)

1303 / 1 = 1303 (the remainder is 0, so 1 is a divisor of 1303)
1303 / 2 = 651.5 (the remainder is 1, so 2 is not a divisor of 1303)
1303 / 3 = 434.33333333333 (the remainder is 1, so 3 is not a divisor of 1303)
...
1303 / 1302 = 1.0007680491551 (the remainder is 1, so 1302 is not a divisor of 1303)
1303 / 1303 = 1 (the remainder is 0, so 1303 is a divisor of 1303)

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 1303 (i.e. 36.09709129556). 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 $\frac{N}{d} = D$ )

1303 / 1 = 1303 (the remainder is 0, so 1 and 1303 are divisors of 1303)
1303 / 2 = 651.5 (the remainder is 1, so 2 is not a divisor of 1303)
1303 / 3 = 434.33333333333 (the remainder is 1, so 3 is not a divisor of 1303)
...
1303 / 35 = 37.228571428571 (the remainder is 8, so 35 is not a divisor of 1303)
1303 / 36 = 36.194444444444 (the remainder is 7, so 36 is not a divisor of 1303)