0x4000000000

0x4000000000 is a hexadecimal integer constant written with the 0x prefix, representing the value 4 followed by nine zeros in base 16. In decimal, this value is 274,877,906,944. It is also equal to 2^38 and to 256 gibibytes (GiB) of bytes, since 1 GiB = 2^30 bytes. In binary, it is a single 1 bit at position 38 (counting from zero).

In computer science, such a power-of-two value is commonly used as a memory size, block size, or bitmask. As a literal, 0x4000000000 is within the range of a 64-bit unsigned integer, but may overflow a 32-bit type depending on language and compiler; many languages would require long or unsigned long long to represent it.

Context examples: It could denote an address or a mask in low-level code. If used as a size, it corresponds to 256 GiB, a notable boundary in memory allocations and page sizes. In hex, the appearance of 0x4000000000 often signals a boundary or allocation aligned to 2^38 bytes.