Table schema:
CREATE TABLE table_16729930_18 (sspec_number VARCHAR, tdp VARCHAR, model_number VARCHAR)

Question: For a processor with model number atom e665c and a TDP of 3.6 W, what is the sSpec number?
SQL: SELECT sspec_number FROM table_16729930_18 WHERE tdp = "3.6 W" AND model_number = "Atom E665C"