Can we extract max value using regexp_substr in mysql?

I get a dynamic string with values separated by comma. Need to extract max value using regexp_substr.

e.g "55,222,3,4000,10" I need to extract 4000 in the above case using regex in MySQL.

 

I'd do this using an array. Something like:

<?php
   $numbers = array(55,222,3,4000,10);
   foreach ($numbers as $i);
   echo max($numbers);
?>

Code (markup):

Example: https://onecompiler.com/php/3yrpmwhvp