Hi,
No, it's not possible as parenthesis are added in the K2 item model file (which is not the right place to do this).
If you want to achieve this without hacking K2, create a template override and add this php code in the template override file of the item (before html code starts) :
//Including item model file
require_once(JPATH_COMPONENT.DS.'models'.DS.'item.hp');
$model = new K2ModelItem();
//Getting item num of votes (only the value)
$vote = $model->getRating($this->item->id);
//Setting the new value with text
if (!is_null($vote))
$rating_count = intval($vote->rating_count);
else
$rating_count = 0;
$this->item->numOfvotes = $rating_count." ".( $rating_count > 1 ? JText::_('K2_VOTES') : JText::_('K2_VOTE') );
