It consists of thirteen boys : Leeteuk , Eunhyuk , Siwon , Ryeowook , Kyuhyun , Heechul , Han Geng , Kibum , Kangin , Sungmin , Shindong , Yesung , and Donghae . The group debut with 13 members : Leeteuk ( Leader ) , Heechul , Han Geng , Yesung , Kangin , Shindong , Sungmin , Eunhyuk , Donghae , Siwon , Ryeowook , Kibum and Kyuhyun , they are one of the largest boy bands in the world .