What does 4649 mean?

4649 meaning in Urban Dictionary

Japanese slang for yoroshiku. The first 4 is pronounced "yo", the 6 "ro", the next 4 "shi" plus the 9 "ku". These readings originate from what sort of figures are pronounced in Japanese. 4 can be "shi" or "yon", 6 is "roku" and 9 is "kyuu" or "ku".