noun
satisfying number; milestone number
Internet slang for a number that feels satisfying or special, such as round numbers (10000), repeating digits (33333), or sequential patterns (12345). Often used for view counts, odometer readings, game scores, etc. Abbreviation of 切りのいい番号.
動画の再生回数がキリ番になったらスクショを撮る。
I take a screenshot when the video's view count hits a satisfying number.
車の走行距離が77777kmのキリ番を達成した。
My car's odometer reached the satisfying number of 77777 km.
The full phrase from which キリ番 is abbreviated. More formal and explicit.
Abbreviation of 切りのいい番号 (kirinoii bangō, 'a round or satisfying number'). The キリ part comes from 切り (kiri, 'cut, end, break'), implying a clean stopping point.