Note: Australia is generally considered to be a continental landmass, rather than an island. If however one does count Australia among the islands it, not Greenland, would be the largest in the world (unless one also considered Antarctica an island).
... (589 miles) long, and 25 to 170 km (16 to 105 miles) wide, with an area of 78,000 km² (24,560 sq. miles). The capital of Sakhalin is Yuzhno Sakhalinsk[?] (Japanese: ...