Cognomen Djahan (Джахан 
, Djahan 
) , around the world, is a rare last name. The cognomen Djahan is habitual in Ivory Coast, where it is a rare surname, Belarus, where it is a very rare surname, and Kyrgyzstan. Measured by absolute frequency, this name is the most popular in Ivory Coast, Indonesia, and France. Also, Djahan is the forename as well as the last name.