Weird. From my side
julia> using SpecialFunctions
julia> gamma(big(3.6e13))
7.882861104028365451673058070377064242970022825665897715265241972922672893761775e+472392288679098
julia> @which gamma(big(3.6e13))
gamma(x::BigFloat) in SpecialFunctions at /Users/gerzaguet/.julia/packages/SpecialFunctions/mFAQ4/src/gamma.jl:578
(testSpecialFunctions) pkg> st
Project testSpecialFunctions v0.1.0
Status `~/testSpecialFunctions/Project.toml`
[276daf66] SpecialFunctions v1.3.0
(testSpecialFunctions) pkg>