What are the divisors of 2770?

1, 2, 5, 10, 277, 554, 1385, 2770

There is a total of 8 positive divisors.
The sum of these divisors is 5004.
The arithmetic mean is 625.5.

4 even divisors

2, 10, 554, 2770

4 odd divisors

1, 5, 277, 1385

How to compute the divisors of 2770?

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 2770 by each of the numbers from 1 to 2770 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)

2770 / 1 = 2770 (the remainder is 0, so 1 is a divisor of 2770)
2770 / 2 = 1385 (the remainder is 0, so 2 is a divisor of 2770)
2770 / 3 = 923.33333333333 (the remainder is 1, so 3 is not a divisor of 2770)
...
2770 / 2769 = 1.0003611412062 (the remainder is 1, so 2769 is not a divisor of 2770)
2770 / 2770 = 1 (the remainder is 0, so 2770 is a divisor of 2770)

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 2770 (i.e. 52.630789467763). 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 $\frac{N}{d} = D$ )

2770 / 1 = 2770 (the remainder is 0, so 1 and 2770 are divisors of 2770)
2770 / 2 = 1385 (the remainder is 0, so 2 and 1385 are divisors of 2770)
2770 / 3 = 923.33333333333 (the remainder is 1, so 3 is not a divisor of 2770)
...
2770 / 51 = 54.313725490196 (the remainder is 16, so 51 is not a divisor of 2770)
2770 / 52 = 53.269230769231 (the remainder is 14, so 52 is not a divisor of 2770)