Use a Schwartzian-transformation, e.g.

use strict;

my @array = qw(abc1 abc32 abc64 abc8 abc16);

my @sorted_array = map { $_->{string} }
                    sort { $b->{number} <=> $a->{number} }
                      map { /(\d+$)/; { string => $_, number => $1 } }
                        @array;
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