# What is perfect number and write a C program to check given number is perfect number or not

(@thiyagarajan)
Eminent Member
Joined:2 years  ago
Posts: 26
27/01/2017 9:45 am

What is perfect number and write a C program to check given number is perfect number or not

Joined:6 years  ago
Posts: 26
10/02/2017 7:04 am

What is perfect number?

A number is considered as perfect number when it satisfies the below conditions.

• It should be a positive number
• When the sum of it's divisors (excluding that number) are equal to that number

Example for perfect numbers:

6, 28, 496, 8128

Description:

1 + 2 + 3 = 6

1 + 2 + 4 + 7 + 14 = 28

C program to check given number is perfect number or not:

Please refer below C program to check whether given number is perfect number or not.

#include<stdio.h>

int main()

{

int number, sum=0, i=1;

printf("Please enter a number to check perfect number\n");

scanf("%d",&number);

while(i<number)

{

if(number%i==0)

{

sum=sum+i;

}

i++;

}

if(sum==number)

printf("\nEntered number %d is a perfect number",i);

else

printf("\nEntered number %d is not a perfect number",i);

return 0;

}

Output:

Please enter a number to check perfect number

28

Entered number 28 is a perfect number

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