Hi there,

Unfortunately, it is not possible to remove the number of members from a group page through backend setting but you can modify this PHP file (JoomlaRootFolder/components/com_easysocial/themes/wireframe/groups/item/default.php) to achieve this.

I already help you to modify the default.php file. So you can just download my attached file and replace into this template override file location (JoomlaFolder/templates/YourCurrentTemplate/html/com_easysocial/groups/item/default.php) so you do not need to do this changes again when you trying to update to the next release version.