CREATE TABLE "table1_17251764_1" (
  "municipality" text,
  "shire" text,
  "population" real,
  "area_in_km_2" text,
  "density_in_inhab_km_2" text,
  "distance_to_san_sebastians_city_centre_in_km" text
);

Question: how many shire in the land of area in km 2 is 27.17
SQL: SELECT COUNT("shire") FROM "table1_17251764_1" WHERE "area_in_km_2"='27.17';