|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, or Finnish Biljoona) 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, Bulgarian милиард, Russian миллиард, Czech miliarda, Arabic مليار, Romanian miliard, Swedish miljard, Norwegian milliard, Turkish milyar, Esperanto miliardo).
Selected 10-digit numbers (1,000,000,000–9,999,999,999)
- 1000000007 – smallest prime number with 10 digits.
- 1023456789 – smallest pandigital number in base 10.
- 1026753849 – smallest pandigital square that includes 0.
- 1073676287 – 15th Carol number.
- 1073741824 = 230
- 1073807359 – 14th Kynea number.
- 1129760415 – 23rd Motzkin number.
- 1134903170 – 45th Fibonacci number.
- 1162261467 = 319
- 1220703125 = 513
- 1234567890 – pandigital number with the digits in order.
- 1311738121 – 25th Pell number.
- 1382958545 – 15th Bell number.
- 1406818759 – 30th Wedderburn–Etherington number.
- 1836311903 – 46th Fibonacci number.
- 1882341361 – The least prime whose reversal is both square (403912) and triangular (triangular of 57121).
- 1977326743 = 711
- 2147483647 – 8th Mersenne prime and the largest signed 32-bit integer.
- 2147483648 = 231
- 2176782336 = 612
- 2214502422 – 6th primary pseudoperfect number.
- 2357947691 = 119.
- 2971215073 – 11th Fibonacci prime (47th Fibonacci number).
- 3166815962 – 26th Pell number.
- 3192727797 – 24th Motzkin number.
- 3323236238 – 31st Wedderburn–Etherington number.
- 3405691582 – hexadecimal CAFEBABE; used as a placeholder in programming.
- 3405697037 – hexadecimal CAFED00D; used as a placeholder in programming.
- 3735928559 – hexadecimal DEADBEEF; used as a placeholder in programming.
- 3486784401 = 320
- 4294836223 – 16th Carol number.
- 4294967291 – Largest prime 32-bit unsigned integer.
- 4294967295 – Maximum 32-bit unsigned integer (hexadecimal FFFFFFFF).
- 4294967296 = 232
- 4294967297 – the first composite Fermat number.
- 4295098367 – 15th Kynea number.
- 4807526976 – 48th Fibonacci number.
- 5784634181 – 13th alternating factorial.
- 6103515625 = 514
- 6210001000 – only self-descriptive number in base 10.
- 6227020800 = 13!.
- 6975757441 = 178
- 6983776800 – 15th colossally abundant number.
- 7645370045 – 27th Pell number.
- 7778742049 – 49th Fibonacci number.
- 7862958391 – 32nd Wedderburn–Etherington number.
- 8589869056 – 6th perfect number.
- 8589934592 = 233
- 9043402501 – 25th Motzkin number.
- 9814072356 – largest square pandigital number, largest pandigital pure power.
- 9876543210 – largest number without redundant digits.
- 9999999967 – greatest prime number with 10 digits.
Sense of scale
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:
- 109 seconds is 114 days short of 32 calendar years (≈ 31.7 years).
- About 109 minutes ago, the Roman Empire was flourishing and Christianity was emerging. (109 minutes is roughly 1,900 years.)
- About 109 hours ago, modern human beings and their ancestors were living in the Stone Age (more precisely, the Middle Paleolithic). (109 hours is roughly 114,000 years.)
- About 109 days ago, Australopithecus, an ape-like creature related to an ancestor of modern humans, roamed the African savannas. (109 days is roughly 2.7 million years.)
- About 109 months ago, dinosaurs walked the Earth during the late Cretaceous. (109 months is roughly 82 million years.)
- About 109 years—a gigaannus—ago, the first multicellular eukaryotes appeared on Earth.
- It takes approximately 95 years to count from one to one billion in a single sitting. 
- The universe is thought to be about 13.8 × 109 years old.
- 109 inches is 15,783 miles (25,400 km), more than halfway around the world and thus sufficient to reach any point on the globe from any other point.
- 109 metres (called a gigameter) is almost three times the distance from the Earth to the Moon.
- 109 kilometres is over six times the distance from the Earth to the Sun.
- The possession of assets with total value of 109 United States dollars would place a person among the world's wealthiest individuals.
- As visualized in a work by artist Michael Marcovici, this amount of money in stacks of hundred-dollar bills can fit on twelve wrapped pallets.
- A billion square inches would be a square about one half mile on a side.
- A piece of finely woven bed sheet cloth that contained a billion holes would measure about 500 square feet (46 m2), large enough to cover a moderate sized apartment.
- There are a billion cubic millimeters in a cubic meter.
- A billion grains of table salt or granulated sugar would occupy a volume of about 2.5 cubic feet (0.071 m3).
- A billion cubic inches would be a volume comparable to a large commercial building slightly larger than a typical supermarket.
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.
- "How many is a billion?". oxforddictionaries.com.
- "greatest prime number with 10 digits". Wolfram Alpha. Retrieved July 15, 2014.
- "How much is a billion?". Math Forum. Retrieved 8 May 2015.
- "Cosmic Detectives". The European Space Agency (ESA). 2013-04-02. Retrieved 2013-05-01.
- Infosthetics (2009-01-14). One Billion Dollar (Most Expensive Artwork Ever), viewed 2010-06-17.