Definition of septillion in English:

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Pronunciation: /sɛpˈtɪljən/

cardinal number (plural septillions or (with numeral) same)

1A thousand raised to the eighth power (1024).
Example sentences
  • This is a septillion times longer than the current age of the universe.
  • Translated into arithmetical terms, the result is 79 octillion, 228 septillion, 162 sextillion, 514 quintillion, 270 quadrillion with 15 zeros attached; that is 79,228,162,270,000,000,000,000,000.
  • Naturally occurring wormholes, if they exist at all, are likely to be extremely small, about 10 septillion times smaller than a typical atom.
1.1 dated, chiefly British A million raised to the seventh power (1042).


Late 17th century: from French, from million, by substitution of the prefix septi- 'seven' (from Latin septimus 'seventh') for the initial letters.

Words that rhyme with septillion

billion, jillion, million, bajillion, modillion, multibillion, multimillion, pillion, sextillion, squillion, trillion, zillion

For editors and proofreaders

Line breaks: sep¦til|lion

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