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_17 (area__km²_ INTEGER, mean_household_size__in_2006_ VARCHAR)

### Question ###
What is the highest Area that has a Mean Household Size of 3.1 persons?

### Accurate SQL ###

SELECT MAX(area__km²_) FROM table_name_17 WHERE mean_household_size__in_2006_ = "3.1 persons"