Names for Big Numbers

Around 1484, Nicolas Chuquet invented several words in French for large numbers. These were billion, trillion, quadrillion, quintillion, sextillion, septillion, octillion, and nonillion, which he used to denote the second through ninth powers of a million. So, a billion was 10¹² (or 1,000,000,000,000), and a trillion was 10¹⁸.

Around the middle of the 17^th century, however, some French arithmeticians started to use these words to instead denote the third through tenth powers of a thousand. This usage eventually became standard in the United States, while the older usage survived in Britain until 1974, when Britain adopted the American usage. So, until 1974, most of the names in the table below stood for different numbers in Britain than they did in America.

Name of number	Value (U.S.)	Old value (U.K.)
Thousand	103	103
Million	106	106
Millard	-	109
Billion	109	1012
Trillion	1012	1018
Quadrillion	1015	1024
Quintillion	1018	1030
Sextillion	1021	1036
Septillion	1024	1042
Octillion	1027	1048
Nonillion	1030	1054
Decillion	1033	1060
Undecillion	1036	1066
Duodecillion	1039	1072
Tredecillion	1042	1078
Quattuordecillion	1045	1084
Quindecillion	1048	1090
Sexdecillion	1051	1096
Septendecillion	1054	10102
Octodecillion	1057	10108
Novemdecillion	1060	10114
Vigintillion	1063	10120
Googol	10100	10100
Centillion	10303	10600

View more names for big numbers

The current usage is known as "short scale," while the old British usage is referred to as "long scale."

Until the word "googolplex" began appearing in dictionaries, centillion was the highest lexicographically recognized named number in the English language.

You'll notice that "zillion" does not appear in the list above. "Zillion" is not a real number word.

See also Names for Big Numbers in Indian English. You may also find Greek metric prefixes interesting as well.