Il numero romano CCLXVI nel sistema decimale vale: 266.
CCLXVI in latino si scrive ducenti sexaginta sex,
mentre in italiano duecentosessantasei.
CCXLVII, CCXLVIII, CCXLIX, CCL, CCLI, CCLII, CCLIII, CCLIV, CCLV, CCLVI, CCLVII, CCLVIII, CCLIX, CCLX, CCLXI, CCLXII, CCLXIII, CCLXIV, CCLXV, CCLXVII, CCLXVIII, CCLXIX, CCLXX, CCLXXI, CCLXXII, CCLXXIII, CCLXXIV, CCLXXV, CCLXXVI, CCLXXVII, CCLXXVIII, CCLXXIX, CCLXXX, CCLXXXI, CCLXXXII, CCLXXXIII, CCLXXXIV, CCLXXXV