#!/usr/bin/perl

use warnings;

sub func {
    $a =~ s/.*_(\d+)$/$1/;
    $b =~ s/.*_(\d+)$/$1/;

    $a <=> $b;
}

my @array = ("0x4b82_555","0x4b82_5", "0x4b82_58","0x4b82_651", "0x4b8
+2_551");
my @result = sort func @array;
print "@result";
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The above code will give the result as you want.