6. Reverse a Number

 #include <stdio.h>

int main() {

    int num, rev = 0, rem;

    printf("Enter a number: ");

    scanf("%d", &num);

    while(num != 0) {

        rem = num % 10;

        rev = rev * 10 + rem;

        num /= 10;

    }

    printf("Reversed: %d\n", rev);

    return 0;

}