C Exercises: Check whether a given number is Deficient or not

Last update on August 05 2025 12:55:41 (UTC/GMT +8 hours)

4. Deficient Number Check Variants

Write a program in C to check whether a given number is Deficient or not.

Test Data
Input an integer number: 15

Sample Solution:

C Code:

#include <stdio.h>
#include <stdbool.h>
#include <math.h>

// Function to calculate the sum of divisors of a number
int getSum(int n)
{
    int sum = 0;
    for (int i = 1; i <= sqrt(n); i++) // Loop through numbers from 1 to the square root of 'n'
    {
        if (n % i == 0) // Check if 'i' is a divisor of 'n'
        {
            if (n / i == i)
                sum = sum + i; // If 'i' is a divisor and is equal to the square root of 'n', add it to 'sum'
            else
            {
                sum = sum + i; // Add 'i' to 'sum'
                sum = sum + (n / i); // Add 'n / i' to 'sum'
            }
        }
    }
    sum = sum - n; // Subtract the number 'n' from the sum of its divisors
    return sum; // Return the sum of divisors
}

// Function to check if a number is a deficient number
bool checkDeficient(int n)
{
    return (getSum(n) < n); // Return true if the sum of divisors is less than 'n', otherwise return false
}

// Main function
int main()
{
    int n;
    printf("\n\n Check whether a given number is Deficient or not:\n");
    printf(" -----------------------------------------------------\n");
    printf(" Input an integer number: ");
    scanf("%d", &n); // Read an integer from the user and store it in variable 'n'

    // Check if the number is deficient and print the result
    checkDeficient(n) ? printf(" The number is Deficient.\n") : printf(" The number is not Deficient.\n");

    return 0;
}

Sample Output:

 Input an integer number: 15                                                                                  
 The number is Deficient.

Visual Presentation:

C programming: Check whether a given number is Deficient or not.

Flowchart:

For more Practice: Solve these Related Problems:

Write a C program to check if a number is deficient and output its sum of proper divisors.
Write a C program to compare a number's divisor sum to itself and classify it as deficient, perfect, or abundant.
Write a C program to check deficiency using an optimized loop for divisor calculation.
Write a C program to test the deficiency of numbers and output detailed divisor information.

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