Question: In what division was there a population density in km2 of 4,491.8 in 2011?
Schema: create table table_24027047_1 (administrative_division varchar, population_density___km²_2011_ varchar, PRIMARY KEY (administrative_division))
SQL: select administrative_division from table_24027047_1 where population_density___km²_2011_ = "4,491.8"