Currently the fastest library for factorization and primality checking in the interval 0;2^64 that is available in Crates.io and possibly in the entire Rust-lang ecosystem. Algebraic definitions of primality and factorization are used, permitting checks like -127.is_prime() to return true and unique factorizations to be considered unsigned.
Currently implements these functions
Legendre symbol
Additionally this library has an implementation of the previous NT functions for arbitrary-precision integers, plus some elementary arithmetic. Multiplication utilizes Karatsuba algorithm, otherwise all other arithmetic can be assumed to be naive.
Usage is fairly simple
rust
// include NT functions
use number_theory::traits::NumberTheory;
// include arbitrary-precision arithmetic
use number_theory::arithmetic::mpz::Mpz;
// Sign, generally unnecessary for ENT
//use number_theory::arithmetic::sign::Sign;
// unsigned from string, defaults to Sign::Positive
let mersenne = Mpz::u_from_string("127");
assert_eq!(mersenne.is_prime(), true);