Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_21979779_1 (no INTEGER, production_code VARCHAR)

### Question ###
what is the biggest series episode number whose production code is 2t7211?

### Accurate SQL ###

SELECT MAX(no) FROM table_21979779_1 WHERE production_code = "2T7211"