I feel like the signed representation makes the most sense, but whatev. If the object is to represent high bases in an inscrutable fashion, there are plenty of Unicode characters out there. If it's to map every printable ASCII string to an integer value, you could use a mixed radix approach where the first digit is (at most) base-94 and the rest are base-95. (There are 95 printable ASCII characters, you missed these: {|}~)