What are the divisors of 2969?

1, 2969

There is a total of 2 positive divisors.
The sum of these divisors is 2970.
The arithmetic mean is 1485.

2 odd divisors

1, 2969

How to compute the divisors of 2969?

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 2969 by each of the numbers from 1 to 2969 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)

2969 / 1 = 2969 (the remainder is 0, so 1 is a divisor of 2969)
2969 / 2 = 1484.5 (the remainder is 1, so 2 is not a divisor of 2969)
2969 / 3 = 989.66666666667 (the remainder is 2, so 3 is not a divisor of 2969)
...
2969 / 2968 = 1.0003369272237 (the remainder is 1, so 2968 is not a divisor of 2969)
2969 / 2969 = 1 (the remainder is 0, so 2969 is a divisor of 2969)

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 2969 (i.e. 54.488530903301). 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 $\frac{N}{d} = D$ )

2969 / 1 = 2969 (the remainder is 0, so 1 and 2969 are divisors of 2969)
2969 / 2 = 1484.5 (the remainder is 1, so 2 is not a divisor of 2969)
2969 / 3 = 989.66666666667 (the remainder is 2, so 3 is not a divisor of 2969)
...
2969 / 53 = 56.018867924528 (the remainder is 1, so 53 is not a divisor of 2969)
2969 / 54 = 54.981481481481 (the remainder is 53, so 54 is not a divisor of 2969)