Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_6 (inegi_code INTEGER, municipal_seat VARCHAR, area__km2_ VARCHAR)

### Question ###
What is the inegi code for mexicali with 13,700 km area?

### Accurate SQL ###

SELECT AVG(inegi_code) FROM table_name_6 WHERE municipal_seat = "mexicali" AND area__km2_ > 13 OFFSET 700