Meanings
plural quadrilliards
- rareA thousand million million million million: 1 followed by twenty-seven zeros, 10²⁷.
Your estimation was quite accurate. In a body of 75 kg of water, there are roughly 2.5 x 10^28. That's 25 octillion (US) or 25 quadrilliard (EU).
2003 December 3, arie, “Re: Why Women "Test" Men, and What Men can Do About It”, in alt.support.loneliness (Usenet), message-ID <bqkc2m$dg9$1@news.tudelft.nl>3 more examples
Ugh. An Australian should use Australian numbers (the same as British), not American. 10^27 is 1,000 quadrillion (or a quadrilliard). An octillion would be 10^48.
2002 June 19, bruce, “Re: Australians did it again! (?)”, in alt.fan.robert-jordan (Usenet), message-ID <cs9qea.as3.ln@ID-92747.user.dfncis.de>There are weak keys in the sense that their use by foisting chosen plaintexts can be proved, which could be interesting for chip cards with a ‘burnt-in key’. First of all, however, these keys can be easily avoided—one only needs to XOR all subkeys with the hexadecimal number 0x0dae—and second, the probability that such a key can be caught is 2⁻⁹⁶; that is about one out of 10²⁹ randomly selected keys (this number even has a name: 100 quadrilliards).
2007, Reinhard Wobst, “Life After DES: New Methods, New Attacks”, in Angelika Shafir, transl., Cryptology Unlocked, John Wiley & Sons, Ltd, →ISBN, section 3 (IDEA: A Special-Class Algoritmh), subsection 5 (Cryptanalyzing IDEA), page 239In the European system, 10⁹ is a milliard, 10¹² is a billion, 10¹⁵ is a billiard, 10¹⁸ is a trillion, 10²¹ is a trilliard, 10²⁴ is a quadrillion, and 10²⁷ is a quadrilliard. To avoid confusion in expressing these numbers, the SI prefixes are preferred.
2014 May 16, Lela Buckingham, “Chapter 3: Systems of Measurement”, in Fundamental Laboratory Mathematics: Required Calculations for the Medical Laboratory Professional, Philadelphia: F. A. Davis Company, →ISBN, Box 3-3: Terms for Large Numbers, page 47Synonyms: a short scale octillion
Synonyms & antonyms
numeralA thousand million million million million: 1 followed by twenty-seven zeros, 10²⁷.
Origin
- Frenchquadrilliard
- Englishquadrilliard
From French quadrilliard, equivalent to quadri- + -illiard.
More words from French
Full word history & related roots →Translations
Spanish cuatrillardo
- cuatrillardo10<sup>27</sup>
Cite this entry
quadrilliard. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/quadrilliard
“quadrilliard.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/quadrilliard. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “quadrilliard,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/quadrilliard.
Source: quadrilliard on Wiktionary, CC BY-SA 4.0.