Display total number of posts using a shortcode. Source: https://codex.wordpress.org/Function_Reference/wp_count_posts

shortcode-published-pages-count.php

<?php

// Display the total number of published pages using the shortcode [published-pages-count]
function customprefix_total_number_published_pages($atts) {
    return wp_count_posts('page')->publish;
}
add_shortcode('published-pages-count', 'customprefix_total_number_published_pages');

shortcode-published-posts-count.php

<?php

// Display the total number of published posts using the shortcode [published-posts-count]
function customprefix_total_number_published_posts($atts) {
    return wp_count_posts('post')->publish;
}
add_shortcode('published-posts-count', 'customprefix_total_number_published_posts');