Hi rhesa,
As I understand it (and a Devel::Peek::Dump($num) would confirm it), $num is created as a double (53 bits of precision), which of course, can't accurately handle the 58-bit integer 1.44115188075868217e17.

One of the things I'm wondering is why perl has been set up to assign integral values like 1.44115188075868217e17 to a "double" on 64-bit integer builds - even when 'use integer' is specified. I suspect it's some sort of 32-bit legacy, but I don't really know.

Thanks for the feedback.

Cheers,
Rob