Are 0, 1, 2, 3, 4....... also considered Romaji?


Are 0, 1, 2, 3, 4....... also considered Romaji? If they are not written using
kanji?




No. ローマ字 (Roman script) is actually an alternative name for ラテン文字 (Latin
script), which only refers to A, B, ..., Z. In Japanese, ローマ字 also means
transcribing Japanese words using Latin alphabet, but that's an extension of
the original meaning.

  * A, B, C, ...: [Latin/Roman script](https://en.wikipedia.org/wiki/Latin_script) ラテン文字／ローマ(文)字
  * 0, 1, 2, ...: [Arabic numeral](https://en.wikipedia.org/wiki/Arabic_numerals) アラビア数字
  * I, II, III, ...: [Roman numeral](https://en.wikipedia.org/wiki/Roman_numerals) ローマ数字




No. ローマ字 (Roman script) is actually an alternative name for ラテン文字 (Latin
script), which only refers to A, B, ..., Z. In Japanese, ローマ字 also means
transcribing Japanese words using Latin alphabet, but that's an extension of
the original meaning.

  * A, B, C, ...: [Latin/Roman script](https://en.wikipedia.org/wiki/Latin_script) ラテン文字／ローマ(文)字
  * 0, 1, 2, ...: [Arabic numeral](https://en.wikipedia.org/wiki/Arabic_numerals) アラビア数字
  * I, II, III, ...: [Roman numeral](https://en.wikipedia.org/wiki/Roman_numerals) ローマ数字

