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_27776266_1 (title VARCHAR, production_code VARCHAR)

### Question ###
What was the title of the episode with a production code of 3x6404?

### Accurate SQL ###

SELECT title FROM table_27776266_1 WHERE production_code = "3X6404"