Math::BigInt 19937! = 2.174930234150431374566653562e77066 time: 104.69734287262 Math::Pari 19937! = 2.174930234150431374566653166e77066 time: 0.00255584716 ^ PP::LogFact 19937! = 2.174930232142160900000000000e77066 (time: 0.030866) ^