Last name Ijen (Ijen 
) , all over the world, is a rare family name. The cognomen Ijen is habitual in Indonesia, where it is a rare surname, Nigeria, where it is a very rare surname, and Philippines, where it is an extremely rare surname. Not in comparison with a country's population, it most frequently occurs in Indonesia, Nigeria, and China. Also, Ijen is the forename as well as the last name.