- substr: documentation ( source)
- chunk_split: documentation ( source)
- substr_replace: documentation ( source)
<?php
$price = 987536453;
$last_digit = substr($price, -1, 1);
echo $last_digit."<br />\n";
$price = substr_replace($price, "", -1, 1);
$price = chunk_split($price, 2, ",").$last_digit;
echo $price;