# C Program to Find All Factors of a Number using For Loop

• Write a C program to print all factors of a number.

Required Knowledge

• C printf and scanf functions
• For loop in C

A number N is a factor of number M, if and only if N divides M completely leaving no remainder(M % N = 0). For example, 4 is a factor of 40 because 4 divides 40 without leaving any remainder.
40 / 4 = 10. and 40 % 4 = 0;

Here is the list of all factors of 40 : 1 2 4 5 8 10 20 40

Algorithm to find all factors of a number N
Check with every number from 1 to N, whether it divides N completely or not.
Let, i be any number between 1 to N

• If(N % i == 0), then i is a factor of N
• If(N % i != 0), then i is not a factor of N

### C program to find all factors of a number using for loop

#include <stdio.h>

int main() {
int counter, N;
/*
* Take a number as input from user
*/
printf("Enter a Number\n");
scanf("%d", &N);

printf("Factors of %d\n", N);

/*Check for every number between 1 to N,
whether it divides N */
for(counter = 1; counter <= N; counter++) {
if(N%counter == 0) {
printf("%d ", counter);
}
}

return 0;
}

Output

Enter a Number
40
Factors of 40
1 2 4 5 8 10 20 40

Enter a Number
37
Factors of 37
1 37