Il numero romano CDI nel sistema decimale vale: 401.
CDI in latino si scrive quadringenti unus,
mentre in italiano quattrocentouno.
CCCLXXXII, CCCLXXXIII, CCCLXXXIV, CCCLXXXV, CCCLXXXVI, CCCLXXXVII, CCCLXXXVIII, CCCLXXXIX, CCCXC, CCCXCI, CCCXCII, CCCXCIII, CCCXCIV, CCCXCV, CCCXCVI, CCCXCVII, CCCXCVIII, CCCXCIX, CD, CDII, CDIII, CDIV, CDV, CDVI, CDVII, CDVIII, CDIX, CDX, CDXI, CDXII, CDXIII, CDXIV, CDXV, CDXVI, CDXVII, CDXVIII, CDXIX, CDXX