# C Program to Find all Perfect Numbers Between 1 to N

In this C program, we will find all perfect numbers between 1 to N using for loop. A perfect number is a positive number, that is equal to sum of its positive divisor.

For Example : 6 is a perfect number as positive factors of 6 are 1, 2 and 3 whose sum is 6.

## C program to print all perfect numbers between 1 to N using for loop

```#include<stdio.h>

int main () {
int num, i, divSum, counter;

printf("Enter a number\n");
scanf("%d", &num);

for(counter = 1; counter <= num; counter++){
/* Find all divisors of a number between
1 to num/2 and add it to divSum */
divSum = 0;
for (i = 1; i <= counter/2; i++) {
if (counter % i == 0) {
divSum += i;
}
}

if (divSum == counter)
printf("%d is Perfect Number\n", counter);
}
return 0;
}
```
Output
```Enter a number
500
6 is Perfect Number
28 is Perfect Number
496 is Perfect Number
```

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