Write a C Program to check whether a number is Prime, Armstrong or perfect number using functions. (Hint=A number is a perfect number if is equal to sum of its proper divisors).

#include<stdio.h> 
#include<conio.h> 

*/

int isPrime(int num)
{
    int i;

    for(i=2; i<=num/2; i++) { if(num%i == 0) { return 0; } } return 1; } int isArmstrong(int num) { int lastDigit, sum, originalNum, digits; sum = 0; originalNum = num; digits = (int) log10(num) + 1; while(num > 0)
    {
        lastDigit = num % 10;

        sum = sum + round(pow(lastDigit, digits));

        num = num / 10;
    }

    return (originalNum == sum);
}

int isPerfect(int num)
{
    int i, sum, n;
    sum = 0;
    n = num;

    for(i=1; i<n; i++)
    {
        if(n%i == 0)
        {
            sum += i;
        }
    }

    return (num == sum);
}


void main()
{
    int num;

    printf("Enter any Number: ");
    scanf("%d", &num);

    if(isPrime(num))
    {
        printf("%d is Prime number.\n", num);
    }
    else
    {
        printf("%d is not Prime number.\n", num);
    }

    if(isArmstrong(num))
    {
        printf("%d is Armstrong number.\n", num);
    }
    else
    {
        printf("%d is not Armstrong number.\n", num);
    }

    if(isPerfect(num))
    {
        printf("%d is Perfect number.\n", num);
    }
    else
    {
        printf("%d is not Perfect number.\n", num);
    }

    getch();
}