CREATE TABLE table_23117208_3 (viewers__millions_ VARCHAR, prod_code VARCHAR)

how many millions of spectator did has the episode whose prod.code was rp#213?
SELECT viewers__millions_ FROM table_23117208_3 WHERE prod_code = "RP#213"
SELECT "viewers__millions_" FROM "table_23117208_3" WHERE "RP#213" = "prod_code"