CREATE TABLE table_23546 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "U.S. viewers  ( million ) " TEXT, "Original air date" TEXT, "Production code" FLOAT)

What is the lowest production code
SELECT MIN("Production code") FROM table_23546
SELECT MIN("Production code") FROM "table_23546"