One sextillionth (10-21): 仄普托,10的负21次幂:zeptosecond.仄普托秒
Etymology语源
From alteration of Latin septem [seven] [from its representing the seventh power of a thousandth] * see septetFrom alteration of Latin septem [seven] [from its representing the seventh power of a thousandth] * 参见 septet