0x8000000000000

0x8000000000000 is a hexadecimal integer literal used in computing to denote the value 2^51. In decimal, this value is 2251799813685248. The literal consists of 13 hexadecimal digits, which corresponds to a 52-bit footprint with a single 1 bit at position 51 (counting from zero) and all other bits cleared.

In practice, 0x8000000000000 can serve as a bit mask or flag within larger bit fields hosted in 64-bit operands. It represents the bit at position 51 and may be used to set, test, or extract that specific bit in systems that employ bitwise operations. Because it is a power of two, its use aligns with common patterns for representing individual flags within compact binary formats.

As with other hexadecimal literals, 0x8000000000000 is language-agnostic in principle but its interpretation depends on the surrounding type. In most modern languages, it is treated as an integer constant that fits within 64-bit unsigned or signed types on platforms that support such widths.

While not a standard constant with a universal meaning, values like 0x8000000000000 are common in low-level programming, where precise control over individual bits is required. They appear in domains such as bitmask construction, protocol field definitions, and performance-oriented code that relies on bitwise arithmetic.

See also: Bit mask, Hexadecimal notation, Power of two.