1×109

1×10^9, read as one billion, is the decimal integer equal to 1,000,000,000. In scientific notation it is used to express large quantities succinctly and to simplify arithmetic with very big or very small numbers. For example, one billion seconds is about 31.7 years, illustrating how large timespans can be described concisely.

In computing and data storage, the decimal interpretation often appears in the form of bytes. 1 gigabyte (decimal) is defined as 10^9 bytes, so 1 GB equals 1×10^9 bytes. By contrast, a binary gibibyte equals 2^30 bytes (1,073,741,824 bytes). These distinctions matter when measuring memory and storage capacity in different contexts.

Ambiguity can arise if the expression is written as plain ASCII 1×109 without the 10^ marker; in such cases it could be interpreted as 109 rather than 1×10^9. For clarity, the conventional notations 1×10^9 or 1e9 are preferred to avoid confusion.

Related concepts include scientific notation, which generalizes this form to any power of ten, and orders of magnitude, which describes how quantities compare across scales.