human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Stellar mass ( M☉ ), Planetary mass ( M⊕ ), Lum. (L 0 ), Type, RHAB ( AU ), RV (cm/s), Period (days)
###Question: What is the highest planetary mass having an RV (cm/s) of 65 and a Period (days) less than 21?
gpt
SELECT MAX Planetary mass ( M⊕ ) FROM table WHERE RV (cm/s) = 65 AND Period (days) < 21