1,000,000,000 (one billion, short scale; one thousand million or one milliard, one yard, long scale) is the natural number following 999,999,999 and preceding 1,000,000,001. With a number, "billion" can be abbreviated as b, bil or bn. In standard form, it is written as 1 × 10 9 . The metric prefix giga indicates 1,000,000,000 times the base unit. Its symbol is G. One billion years may be called an... Wikipedia