What is the smallest area that has a Population Density of 3,216 and a Population larger than 16,650,000?
CREATE TABLE "largest_metropolitan_areas" (
  "rank" real,
  "metropolitan_area" text,
  "country" text,
  "population" real,
  "area_km" real,
  "population_density_people_km" real
);
SELECT MIN("area_km") FROM "largest_metropolitan_areas" WHERE "population_density_people_km"='3,216' AND "population">'16,650,000';