C Program to Display Factors of a Number

In this example, you will learn to find all the factors of an integer entered by the user.

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To understand this example, you should have the knowledge of the following C programming topics:

• C Programming Operators
• C if…else Statement
• C for Loop

This program takes a positive integer from the user and displays all the positive factors of that number.

Factors of a Positive Integer

#include 
int main() {
    int num, i;
    printf("Enter a positive integer: ");
    scanf("%d", &num);
    printf("Factors of %d are: ", num);
    for (i = 1; i <= num; ++i) {
        if (num % i == 0) {
            printf("%d ", i);
        }
    }
    return 0;
}

Output

Enter a positive integer: 60
Factors of 60 are: 1 2 3 4 5 6 10 12 15 20 30 60

In the program, a positive integer entered by the user is stored in num.

The for loop is iterated until i <= num is false.

In each iteration, whether num is exactly divisible by i is checked. It is the condition for i to be a factor of num.

if (num % i == 0) {
            printf("%d ", i);
}

Then the value of i is incremented by 1.