number
short-scale unvigintillion (10⁶⁶; long-scale undecillion); short-scale undecillion (10³⁶; long-scale sextillion)
“Un billion est égal à un million de millions; un trillion, à un million de billions; un quadrillion, à un million de trillions, et ainsi de suite, pour donner l’impressionnante série des quintillions, sextillions, septillions, octillions, nonillions, décillions, undécillions…” — One trillion equals one million million; a quintillion, a million trillion; a septillion, a million quintillion, and so on, to give the impressive series of nonillion, undecillion, tredecillion, quindecillion, septendecillion, novemdecillion, unvigintillion…
From Latin undec(im) + -illion.