Which Basin's Continent is South America, has a Basin Area km 2 larger than 6,144,727, and a Basin Area mi 2 of 238,539?
CREATE TABLE "basins" (
  "basin" text,
  "continent" text,
  "drains_to" text,
  "basin_area_km_2" real,
  "basin_area_mi_2" text
);
SELECT "basin" FROM "basins" WHERE "continent"='south america' AND "basin_area_km_2">'6,144,727' AND "basin_area_mi_2"='238,539';