Bilibino (Russian:Били́бино) is a town and the administrative center of Bilibinsky District in Chukotka Autonomous Okrug, Russia, located at the confluence of the Karalveyem and Bolshoy Keperveyem Rivers (Kolyma's basin), 625 kilometers (388 mi) northwest of Anadyr, the administrative center of the autonomous okrug. With a population of 5,506 as of the 2010 Census, and an estimated population as of 1 January 2015 of 5,592, it is the second largest town in the autonomous okrug after Anadyr.