1000000000

1,000,000,000, written as 1×10^9 in scientific notation, is the natural number that follows 999,999,999. In modern usage it is known as one billion in the short scale, the convention used by most English-speaking countries. Historically, the term billion had different meanings in the long scale, where it denoted 10^12; today the short scale meaning is the standard in most contexts.

In mathematics and everyday counting, 1,000,000,000 is a power of ten (10^9). It is a convenient benchmark in many scientific and engineering contexts, where decimal scales are common and easy to compare with other powers of ten such as 10^6 (million) and 10^12 (trillion).

Prefix and unit contexts place 10^9 under the SI prefix giga- (symbol G). For example, a gigameter or a gigabyte denotes multiples of 10^9 in the respective units. In computing, there is a notable ambiguity: a decimal gigabyte is 10^9 bytes, while a binary gibibyte is 2^30 bytes (1,073,741,824), which often leads to the everyday confusion between GB and GiB.

Applications of the number include large population counts, national budgets, large-scale data measures, and scientific data sets. As a fixed point in the decimal system, 1e9 serves as a common reference in planning, statistics, and technical specifications, and it is frequently encountered in engineering and data analysis.