Equivalent to Ruby's to_i(36) in Javascript

Question

"y851sq2vh4pf".to_i(36) #4504900070017571091

but

parseInt("y851sq2vh4pf",36) //4504900070017571300

How can I implement the Ruby to_i(36) function in Javascript? Why are the behaviors different?

Answer 1

Javascript doesn't have 64 bit integers, it only has double which loses accuracy for integers after 9007199254740992 (2⁵³)

Use a Big Number library like http://silentmatt.com/biginteger/