quattuordecillion
noun
quat·tu·or·de·cil·lion ˌkwä-tə-ˌwȯr-di-ˈsil-yən 
often attributive
US : a number equal to 1 followed by 45 zeros see Table of Numbers
also, British : a number equal to 1 followed by 84 zeros see Table of Numbers
Word History
Etymology
Latin quattuordecim fourteen (from quattuor four + decem ten) + English -illion (as in million) — more at ten
First Known Use
1848, in the meaning defined above