$ perl -wMstrict -le 'print 0xFFFFFFFF'
4294967295
$ perl -wMstrict -le 'print 0xFFFFFFFFF'
Hexadecimal number > 0xffffffff non-portable at -e line 1.
68719476735
$ perl -wMstrict -le 'print 0xFFFFFFFFFFFFFFFFF'
Integer overflow in hexadecimal number at -e line 1.
Hexadecimal number > 0xffffffff non-portable at -e line 1.
2.95147905179353e+20