Bits in variables

How many bits GD variables are using? I’m asking because I’m making game where really big numbers will be a thing and I don’t want suddenly - becoming + or vice versa…

Variables storing number are “double” for native games (i.e on 64 bits: … int_format so you have about 15 significant numbers).
For HTML5 games, number are stored as plain javascript number, which are also “double”:

You can always use really big numbers, but the precision will be always limited to the 15 first numbers (Other will probably be set to 0).

Your best bet is using a string