noun
room number
Refers to the identifying number assigned to a room, such as in a hotel, hospital, or office building.
ホテルの部屋番号を教えてください。
Please tell me the hotel room number.
会議は部屋番号302で行われます。
The meeting will be held in room number 302.
Compound of 部屋 (へや, 'room') and 番号 (ばんごう, 'number').