- rsort: documentation ( source)
- print_r: documentation ( source)
- implode: documentation ( source)
- str_split: documentation ( source)
<?php
$int = 84739173848113;
$string = (string)$int;
$stringParts = str_split($string);
rsort($stringParts);
print_r($stringParts);
echo implode('', $stringParts);