SQL errors

$ cat test.SQL
SET @DB_DATABASE_NAME = 'test_db';
SET @DB_TABLE_NUMBERS = 'name_number';

DROP DATABASE IF EXISTS @DB_DATABASE_NAME;
CREATE DATABASE IF NOT EXISTS @DB_DATABASE_NAME;

USE @DB_DATABASE_NAME;

CREATE TABLE IF NOT EXISTS @DB_TABLE_NUMBERS
(
        `nn_id` INT PRIMARY KEY AUTO_INCREMENT,
        `nn_name` VARCHAR(64) CHARACTER SET utf8,
        `nn_number` VARCHAR(18) CHARACTER SET utf8
);

$ mysql -v -uroot -pXXX < test.SQL
--------------
SET @DB_DATABASE_NAME = 'test_db'
--------------

--------------
SET @DB_TABLE_NUMBERS = 'name_number'
--------------

--------------
DROP DATABASE IF EXISTS @DB_DATABASE_NAME
--------------

ERROR 1064 (42000) at line 4: You have an error IN your SQL syntax; CHECK the manual that corresponds TO your MariaDB server version FOR the RIGHT syntax TO USE near '@DB_DATABASE_NAME' at line 1