Many catalogues of mathematical groups contain things like the monster group, which has 808,017,424,794,512,875,886,459,904,961,710,757,005,754,368,000,000,000 elements. That won't fit in a 64 or even 128 bit integer.
It is common to want to ask a database "tell me all groups of size greater than X, with properties A, B and C". Now, if you have arbitrary sized ints, no problem. If your database (or language) doesn't support big ints, you need to figure out how to do "bigger than X", when you are storing big numbers in some other format, probably strings.
It is common to want to ask a database "tell me all groups of size greater than X, with properties A, B and C". Now, if you have arbitrary sized ints, no problem. If your database (or language) doesn't support big ints, you need to figure out how to do "bigger than X", when you are storing big numbers in some other format, probably strings.