Il numero romano CCCXCVII nel sistema decimale vale: 397.
CCCXCVII in latino si scrive trecenti nonaginta septem,
mentre in italiano trecentonovantasette.
CCCLXXVIII, CCCLXXIX, CCCLXXX, CCCLXXXI, CCCLXXXII, CCCLXXXIII, CCCLXXXIV, CCCLXXXV, CCCLXXXVI, CCCLXXXVII, CCCLXXXVIII, CCCLXXXIX, CCCXC, CCCXCI, CCCXCII, CCCXCIII, CCCXCIV, CCCXCV, CCCXCVI, CCCXCVIII, CCCXCIX, CD, CDI, CDII, CDIII, CDIV, CDV, CDVI, CDVII, CDVIII, CDIX, CDX, CDXI, CDXII, CDXIII, CDXIV, CDXV, CDXVI