# septillion

> English word · Numeral · IPA /sɛpˈtɪljən/

## Definitions
1. A trillion trillion: 1 followed by 24 zeros, 10²⁴.
2. A billion quintillion: 1 followed by 42 zeros, 10⁴².

## Etymology
From French septillion, from sept- (“seven”) + -illion. By surface analysis, sept- + -illion.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/septillion