Cognomen 尔旦 (Erdan 
, 尔旦 
) , throughout the world, is quite a rare family name. The last name 尔旦 is habitual in North Macedonia, where it is quite a rare surname, Turkey, and Ethiopia, where it is a rare surname. Not in comparison with a country's population, this name is the most popular in Turkey, Ethiopia, and China. Likewise, 尔旦 is the forename as well as the last name.