1,000,000,000


1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001. One billion can also be written as b or bn.
In scientific notation, it is written as 1 × 109. The metric prefix giga indicates 1,000,000,000 times the base unit. Its symbol is G.
One billion years may be called an eon in astronomy or geology.
Previously in British English, the word "billion" referred exclusively to a million millions. However, this is no longer common, and the word has been used to mean one thousand million for several decades.
The term milliard can also be used to refer to 1,000,000,000; whereas "milliard" is rarely used in English, variations on this name often appear in :wikt:milliard#Translations|other languages.
In the South Asian numbering system, it is known as 100 crore or 1 arab.

Sense of scale

The facts below give a sense of how large 1,000,000,000 is in the context of time according to current scientific evidence:

Time

A is a cube; B consists of 1000 cubes the size of cube A, C consists of 1000 cubes the size of cube B; and D consists of 1000 cubes the size of cube C. Thus there are A-sized cubes in C; and 1,000,000,000 A-sized cubes in D.

Selected 10-digit numbers (1,000,000,001–9,999,999,999)

1,000,000,001 to 1,999,999,999