Count the number of digits in a number with C. 

#include <stdio.h>

int main()
{
    long long num;
    int count = 0;

    /* Input number from user */
    printf("Enter any number: ");
    scanf("%lld", &num);

    while (num != 0){
        num /= 10;
        count++;
    }

    printf("Total digits: %d", count);

    return 0;
}

Output:-


Enter any number : 564465
Total digits : 6