From Japanese-German FreeDict Dictionary ver. 0.2.0:
[ichi1] [news2] [nf33] 一 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, １, 壱 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 弌 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, (word containing out-dated kanji) 壹 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, [ichi1] [news2] [nf33] いち /ˈitɕi/
(numeric)
(prefix)
ワン・1 (１ can also be read ワン. 壱, 弌 and 壹 are used in legal documents)
eins, eins, 1 (Ziffer in Dokumenten)