Cognomen 尔丹 (尔丹 
, Erdan 
) , in the world, is quite a rare surname. The last name 尔丹 is characteristic of North Macedonia, where it is quite a rare surname, Turkey, and Ethiopia, where it is a rare surname. Measured by absolute frequency, it is the most numerous in Turkey, China, and Ethiopia. Likewise, 尔丹 is the forename as well as the last name.