Yes you can. You have to check if the post view count is higher than 1000, is so, then round it and return it:
function getPostViews($postID) {
$count_key = 'post_views_count';
$count = get_post_meta($postID, $count_key, true);
if($count=='') {
delete_post_meta($postID, $count_key);
add_post_meta($postID, $count_key, '0');
return "0 View";
}
if ($count > 1000) {
return round ( $count / 1000 ,1 ).'K Views';
} else {
return $count.' Views';
}
}