Yuo can also do it this way, count published posts, get settings posts per page, then divide.
$published_posts = wp_count_posts()->publish;
$posts_per_page = get_option('posts_per_page');
$page_number_max = ceil($published_posts / $posts_per_page);
Yuo can also do it this way, count published posts, get settings posts per page, then divide.
$published_posts = wp_count_posts()->publish;
$posts_per_page = get_option('posts_per_page');
$page_number_max = ceil($published_posts / $posts_per_page);