CREATE TABLE table_21734764_1 (population_density___km²_2010_ VARCHAR(255), population_2010_census VARCHAR(255))
What is the population density of the administrative division with a population in 2010 of 264170 according to the census?
    
SQL: SELECT population_density___km²_2010_ FROM table_21734764_1 WHERE population_2010_census = 264170