PHP program to print a number in reverse order

<?php
$num=123456789; // Give the number which you want to print in reverse order
echo $num;
echo "<br>";
$revnum=0;
do{
 $revnum=($revnum *10)+($num % 10);
 $num=(int)($num / 10 );
}while($num>0);
echo $revnum;
?>