The Calculator stores integers to arbitrary precision. Addition, subtraction, and multiplication of integers always yields an exact integer result. (If the result of a division or exponentiation of integers is not an integer, it is expressed in fractional or floating-point form according to the current Fraction mode. See Fraction Mode.)
A decimal integer is represented as an optional sign followed by a sequence of digits. Grouping (see Grouping Digits) can be used to insert a comma at every third digit for display purposes, but you must not type commas during the entry of numbers.
A non-decimal integer is represented as an optional sign, a radix between 2 and 36, a ‘#’ symbol, and one or more digits. For radix 11 and above, the letters A through Z (upper- or lower-case) count as digits and do not terminate numeric entry mode. See Radix Modes, for how to set the default radix for display of integers. Numbers of any radix may be entered at any time. If you press # at the beginning of a number, the current display radix is used.