change the numbers (contrariwise)

int i = 1234;
string s = i.ToString();                        // Convert the int to a string
string r = new string(s.Reverse().ToArray());   // Reverse the string
int j = int.Parse(r);                           // Convert the reversed string to an int

int k = int.Parse(new string(i.ToString().Reverse().ToArray()));

int n = 456;
int getnum= n;
int rev = 0;
while(getnum>0)
{
   r = getnum% 10;
   rev = rev * 10 + r;
   left = getnum/ 10;  //left = Math.floor(left / 10);
}