PHP Automorphic Number Finder Algorithm

automorphic.php

<?php
/*
    PHP Automorphic Number Finder Algorithm
    Author: Lawrence Lagerlof
    License: MIT
*/
$limit = 1000000;
$milestone = $limit / 100;
for ($n = 2; $n <= $limit; $n++) {
    $square = (string) $n * $n;
    $final = substr($square, strlen((string) $n) * (-1), strlen($square));
    if ((string) $n == $final) {
        echo "\n" . 'number  = ' . str_pad($n, strlen($square), ' ', STR_PAD_LEFT) . "\n";
        echo 'squared = ' . $square . "\n\n";
    }
    if (($n % $milestone) === 0) {
        echo ($n / $limit * 100) . " %\n";
    }
}