she looks up the value and apparently it is a specific number, rather than what the text ("immeasurably large number") means. this also didn't come across clearly in the tl.
the japanese numeral system has a name for powers of 10^4, this is the 10^(4*17) and last named number in that system, conceptually like english sexdecillion = 10^(3*17).
after 10^48 they stop having single characters for the numbers:
10^48 極 "extreme"
10^52 恒河沙 "sands of the Ganges river"
10^56 阿僧祇 "asogi", loanword for sanskrit "innumerable" or "countless"
10^60 那由他 "nayuta", loanword for sanskrit "immense number"
10^64 不可思議 "inconceivable"
10^68 無量大数 "immeasurable" or "immeasurably large number"