15E9

15E9 is a numeric literal written in scientific notation, representing 15 × 10^9. In standard decimal form, this equals 15,000,000,000, or fifteen billion.

When notated with units, 15E9 can denote large quantities across different domains. For example, 15E9 bytes is about 15 gigabytes (GB) in decimal notation, which is approximately 13.97 gibibytes (GiB). In frequency terms, 15E9 hertz equals 15 gigahertz (GHz). In population counts or data tallies, it simply indicates fifteen billion items.

In programming and data analysis, 15E9 commonly appears as a floating-point literal in languages that support scientific notation (for example, 15e9 or 15E9). The underlying value is 15,000,000,000, but precision and numeric type (float vs. double or integer) depend on the language and context.