Cognomen 科汉 (Cohan 
, Kochan 
, 科汉 
) , in all the world, is a common surname. The family name 科汉 is characteristic of North Macedonia, where it is quite a common surname, Slovakia, and India, where it is quite a rare surname. Measured by absolute frequency, it is commonest in India, the United States, and Poland. Very seldom, 科汉 is the forename as well as the last name.