big-integer
An arbitrary length integer library for Javascript
jsbn
The jsbn library is a fast, portable implementation of large-number math in pure JavaScript, enabling public-key crypto and other applications on desktop and mobile browsers.
gmp-wasm
Arbitrary-precision Integer, Rational and Float types based on the GMP and MPFR libraries
extra-bigint
A BigInt can represent whole numbers larger than 2⁵³ - 1.