Check whether a number is a Strong number or not with C
#include <stdio.h>

int main()
{
    int i, original, num, lastDigit, sum;
    long fact;

    printf("Enter any number to check Strong number: ");
    scanf("%d", &num);
    original = num;
    sum = 0;

    while (num > 0)
    {
        lastDigit = num % 10;

        fact = 1;
        for (i = 1; i <= lastDigit; i++)
        {
            fact = fact * i;
        }
        sum = sum + fact;

        num = num / 10;
    }

    if (sum == original)
    {
        printf("%d is STRONG NUMBER", original);
    }
    else
    {
        printf("%d is NOT STRONG NUMBER", original);
    }
    return 0;
}

output

Enter any number to check Strong number : 50
 50 is NOT STRONG NUMBER