- Traditional Chinese Character(HanT):
二十一世紀
- Simplified Chinese Character(HanS):
二十一世纪
- Bopomofo(Mandarin Phonetic Symbols): ㄦˋ ㄕˊ ㄧˋ ㄕˋ ㄐㄧˋ (ㄦㄕㄧㄕㄐ)
- Bopomofo(Zhuyin Keyboard Input/IME): -4g6u4g4ru4
- (ASCII) Hanyu Pinyin: "ershiyishiji" "Er4Shi2Yi4Shi4Ji4" "Er4 Shi2 Yi4 Shi4 Ji4" (ESYSJ)
- (Latin) Hànyǔ Pīnyīn: èrShíYìShìJì [ èr Shí Yì Shì Jì ]
- (英文翻譯) English Translation: "twenty-first century"
- (西語翻譯) Traducción Español: "siglo veintiuno"
- (日文翻譯) 日本語翻訳: "21世紀"