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quadrillion

/kwɑˈdɹɪl.i.ən/number, noun

quadrillion is spelled Q-U-A-D-R-I-L-L-I-O-N: 11 letters and 4 syllables. It appears about once in every 8 million words in written English, the 84,254th most frequent word form (wordfreq, 2021 data). As a number, quadrillion means “A thousand trillion (logic: 1,000 × 1,000⁴): 1 followed by fifteen zeros, 10¹⁵” (English Wiktionary, September 2026).

How many letters and syllables are in quadrillion?

Letters11: Q-U-A-D-R-I-L-L-I-O-N
Syllables4 (from its pronunciation)
In writingabout once in every 8 million words; the 84,254th most frequent word form
Wrong spellings searchednone measured in search

Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).

How common is quadrillion?

Quadrillion appears about once in every 8 million words in written English, the 84,254th most frequent word form in the list.

Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).

How do you pronounce quadrillion?

  • US /kwɑˈdɹɪl.i.ən/
  • US /kwɑˈdɹɪl.jən/
  • Australia /kwɔˈdɹɪl.jən/

Quadrillion has 4 syllables (counted from the pronunciation).

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-quadrillion.ogg, En-au-quadrillion.ogg, Wikimedia Commons (author and licence on each file's page).

Forms of quadrillion

  • quadrillions plural

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

What does quadrillion mean?

The meanings the English Wiktionary records, quoted as written there (source below).

number

  1. 1

    BritishUSA thousand trillion (logic: 1,000 × 1,000⁴): 1 followed by fifteen zeros, 10¹⁵.

  2. 2

    AustraliaUKdatedA million trillion (logic: 1,000,000⁴): 1 followed by twenty-four zeros, 10²⁴.

noun

  1. 1

    slangAny very large number, exceeding normal description.

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

Quadrillion in Spanish, French, German and Portuguese

LanguageWords
Frenchbilliard, million de milliards (a thousand trillion (1,000,000,000,000,000); a…), quadrillion (a million trillion, 1024 – see also septillion), milliard, milliards, million (any very large number)
GermanBilliarde (a thousand trillion (1,000,000,000,000,000); a…), Quadrillion (a million trillion, 1024 – see also septillion)
Portuguesemil biliões, quadrilhão, quatrilhão (a thousand trillion (1,000,000,000,000,000); a…), quadrilião m quatrilião, septilhão (a million trillion, 1024 – see also septillion)
Spanishcuatrillón, mil billones (a thousand trillion (1,000,000,000,000,000); a…)

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.

Where does quadrillion come from?

From French quadrillion, from quadri- (“four”) + -illion. By surface analysis, quadr- + -illion.

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

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