it's their representative number(?) i don't know how to call it but it's a number they choose when they first debut, if u watch woollimpick ( their predebut show ) they'll explain it?
i don't remember all their numbers but jibeom 55 is a match with joochan's number which is 33 so, 3355! jangjun 82, because that's korea number(?) as in the phone call front number, as in he wants golcha to be korea representative someday sungyoon *he's not here* 3 bcs he wants golcha to be on the top 3! seungmin 98 bcs he's born in 1998? probably jaehyun 19 bcs he's 19 when he debut! daeyeol 11 bcs his birthday is on 11th february and maybe bcs before they're a 11 member group i'm not sure about tag, donghyun and bomin ?