CREATE TABLE table_214920_1 (land_area VARCHAR, density__pop_per_km2_ VARCHAR)

What is the land area of the RCM having a density of 21.1?
SELECT land_area FROM table_214920_1 WHERE density__pop_per_km2_ = "21.1"
SELECT "land_area" FROM "table_214920_1" WHERE "21.1" = "density__pop_per_km2_"