Word Study
sextillion
CIDE DICTIONARY
sextillion, n. [Formed (in imitation of million) fr. L. sextus sixth, sex six: cf. F. sextilion.].
According to the method of numeration (which is followed also in the United States), the number expressed by a unit with twenty-one ciphers annexed. According to the English method, a million raised to the sixth power, or the number expressed by a unit with thirty-six ciphers annexed. See Numeration. [1913 Webster]
OXFORD DICTIONARY
sextillion, n. (pl. same or sextillions) a thousand raised to the seventh (or formerly, esp. Brit., the twelfth) power (10(21) and 10(36) respectively) (cf. BILLION).
Derivative
sextillionth
Etymology
F f. L sex six, after septillion etc.
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