Cognomen Тятин (Chachin 
, Тятин 
, Tiatin 
) , all around the world, is a rare last name. The cognomen Тятин is characteristic of Estonia, where it is a rare surname, Colombia, and Kazakhstan. Measured by absolute frequency, it is the most numerous in Japan, Russia, and Colombia. Very seldom, Тятин is the forename as well as the last name.