Write a C program to enter any number and check whether the number is Perfect number or not. How to check perfect numbers in C program using loop. Perfect number program in C.

Input number: 6

Output: 6 is perfect number

Proper divisors of 6 are 1, 2, 3

And 1+2+3 = 6. Hence 6 is a perfect number

Happy coding ;)

**Example:**Input number: 6

Output: 6 is perfect number

### Required knowledge

Basic C programming, For loop, If else#### Perfect number

A perfect number is a positive integer which is equal to the sum of its proper positive divisors. For example: 6 is the first perfect numberProper divisors of 6 are 1, 2, 3

And 1+2+3 = 6. Hence 6 is a perfect number

### Program to check perfect number

/** * C program to check whether a number is Perfect number or not */ #include <stdio.h> int main() { int i, num, sum = 0; /* Reads a number from user */ printf("Enter any number to check perfect number: "); scanf("%d", &num); /* Finds the sum of all proper divisors */ for(i=1; i<num; i++) { /* If i is a divisor of num */ if(num%i==0) { sum += i; } } /* Checks whether the sum of proper divisors is equal to num */ if(sum == num) { printf("\n%d is a Perfect number", num); } else { printf("\n%d is not a Perfect number", num); } return 0; }

Output

Enter any number to check perfect number: 6

6 is a Perfect number

6 is a Perfect number

Happy coding ;)

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Thanks for nice post.know details

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