|Cardinal||One billion (short scale)
One thousand million, or one milliard (long scale)
|Ordinal||One billionth (short scale)|
|Factorization||29 · 59|
In scientific notation, it is written as 1 × 109.
Previously in British English (but not in American English), the word "billion" referred to a million millions (1,000,000,000,000). However, this is no longer the case, and the word has been used unambiguously to mean one thousand million (1,000,000,000) for some time. The alternative term "one thousand million" is rare and is used primarily to ease understanding among non-native speakers of English, as many other languages use words similar to "billion" (e.g. Spanish billón) to mean one trillion (1,000,000,000,000 or a million millions).
The term milliard can also be used to refer to 1,000,000,000; whereas "milliard" is seldom used in English, variations on this name often appear in other languages (e.g. Hungarian (Magyar) milliárd, Indonesian miliar, Polish miliard, Danish milliard, Spanish millardo, French milliard, Italian miliardo, Icelandic milljarður, German Milliarde, Hebrew מיליארד, Finnish miljardi, Dutch miljard, Croatian milijarda, Serbian милијарда, Russian миллиард, Czech miliarda, Arabic مليار, Romanian miliard, Swedish miljard, Norwegian milliard, Turkish "milyar").
The facts below give a sense of how large 1,000,000,000 (109) is in the context of time according to current scientific evidence:
A small mountain, slightly larger than Stone Mountain Georgia, United States, would weigh (have a mass of) a billion tons.
A is a cube; B consists of 1000 cubes of type A. C consists of 1000 Bs; and D 1000 Cs. Thus there are 1 million As in C; and 1,000,000,000 As in D.