ord('k') is 107 so it should print 107

Uhm, no.

the first statement should not effect it.

Yes, it should. To quote myself: Setting $# sets the output format for printed numbers. 107 is still a number in my book.

From man perlvar:

       $#      The output format for printed numbers.  This vari­
               able is a half-hearted attempt to emulate awk's
               OFMT variable.  There are times, however, when awk
               and Perl have differing notions of what counts as
               numeric.  The initial value is "%.ng", where n is
               the value of the macro DBL_DIG from your system's
               float.h.  This is different from awk's default
               OFMT setting of "%.6g", so you need to set $#
               explicitly to get awk's value.  (Mnemonic: # is
               the number sign.)

               Use of $# is deprecated.
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Is $# really broken for eons? Where's that from?

Yes it is. Your code is proof.

Abigail