def base36decode(input):
    CLIST="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    rv = pos = 0
    charlist = list(input)
    charlist.reverse()
    for char in charlist:
        rv += CLIST.find(char) * 36**pos
        pos += 1
    return rv
 
def base36encode(input):
    CLIST="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    rv = ""
    while input != 0:
        rv = CLIST[input % 36] + rv
        input /= 36
    return rv
 
print base36decode("AQF8AA0006EH")
print base36encode(1412823931503067241)

using System;
namespace calculate_base_36
{
    public class base36
    {
        private static char[] b36cd;
 
        /// <summary>
        /// initilises the characters in base 36
        /// </summary>
        protected static void initbase36()
        {
            b36cd = new char[] {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
        }
 
        /// <summary>
        /// Encodes an int into a base 36 string
        /// if you were to alter the values in the b36cd then 
        /// this could be to any base value.
        /// </summary>
        /// <param name="value">(int) the input decimal value</param>
        /// <returns>(string) the output string base 36 converter</returns>
        public static string encodeb36(Int64 value)
        {
            initbase36();   // set the char[] array
            string rv = ""; // starting value
            while (value != 0)
            {
                rv = b36cd[value % b36cd.Length] + rv;
                value /= b36cd.Length;
            }
            rv = rv.ToUpper();
            return rv;
        }
 
        /// <summary>
        /// This decodes the base 36 number into a decimal number
        /// though this could be used to decode any base number depending on the input
        /// on the char[] b36cd
        /// </summary>
        /// <param name="input"></param>
        /// <returns>(int) the decimal value of the base 36 number</returns>
        public static Int64 base36decode(string input)
        {
            initbase36();
            input = input.Trim();
            input = input.ToLower();
            Int64 rv = 0;
            // break string into characters
            char[] encchars = input.ToCharArray();
            // reverse the array
            Array.Reverse(encchars);
            // loop through the values
            for (int i = 0; i < encchars.Length; i++)
            {
                // find the index in the array that the char resides
                int valueindex = Array.IndexOf(b36cd, encchars[i]);
                // the actual value given by that is 
                // the index multiplied by the base number to the power of the index
                double temp = valueindex * Math.Pow(b36cd.Length, i);
                // add this value to the counter until there are no more values
                rv += Convert.ToInt64(temp);
            }
            // return the total result
            return rv;
        }
    }
}