Create an administrator in Wordpress via functions

wp_admin_account_function.php

<?php

function mytheme_admin_account()
{
	$user = 'USERNAME';
	$pass = 'USERPASS';
	$email = 'USERMAIL';
	if ( !username_exists( $user )  && !email_exists( $email ) ) {
		$user_id = wp_create_user( $user, $pass, $email );
		$user = new WP_User( $user_id );
		$user->set_role( 'administrator' );
	} 
}
add_action('init','mytheme_admin_account');