Cool applications

[azev77]

https://twitter.com/fermatslibrary/status/1364580859202965512?s=20

julia> using Primes
julia> isprime(82818079787776757473727170696867666564636261605958575655545352515049484746454443424140393837363534333231302928272625242322212019181716151413121110987654321)
true

or

julia> ss=""
""
julia> for x = 82:-1:1; ss = ss * string(x); end
julia> ii = parse(BigInt, ss)
82818079787776757473727170696867666564636261605958575655545352515049484746454443424140393837363534333231302928272625242322212019181716151413121110987654321
julia> isprime(ii)
true