You really are very curious.
I have not developed games with Renpy, but I know it uses Python code. In python 2 (which Renpy 7 uses) integer type is processor word size, which nowadays usually is 64 bit. There is data type long, which should always be at least 64 bits.
I’m just curious, because I wanna know if I could theoretically get above 2147483647 ingame.
I’m quite sure you can, just keep earning money.
In Python 3 which Renpy 8 uses, integer type is unlimited. When game is ported to that new Renpy version you can have unlimited amount of money!
More information can be found with Internet Search Engines or a book about Python. I did not include links here, I do not want this message blocked as SPAM.