septendecillion

noun

sep·​ten·​de·​cil·​lion (ˌ)sep-ˌten-di-ˈsil-yən 

often attributive

US : a number equal to 1 followed by 54 zeros see Table of Numbers

also, British : a number equal to 1 followed by 102 zeros see Table of Numbers

Word History

Etymology

Latin septendecim seventeen (from septem seven + decem ten) + English -illion (as in million) — more at ten

First Known Use

1898, in the meaning defined above