CREATE TABLE table_73415 ("Season no." FLOAT, "Series no." FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" FLOAT, "U.S. Viewers  ( millions ) " CLOB)

which is the biggest production code?
SELECT MAX("Production code") FROM table_73415
SELECT MAX("Production code") FROM "table_73415"