I find it hard to believe that someone simultaneously doesn't know the first thing about bit operations, but has come to the conclusion that they need to find the first 42 bits.

Also, JavaScript's handling of numbers is so weird that it's one of those things that comes up just by virtue of its weirdness. For that reason I'd expect a JS programmer at least have come across but operations.

(edit - I take the original post as a joke too, and that the humour is derived from the juxtaposition)