11111001

11111001 is an eight-bit binary number, often written as 11111001₂. In hexadecimal, it is F9; in unsigned decimal, it equals 249.

As a signed value, interpretation depends on the binary representation used. In two's complement, typical for modern computers, 11111001 represents -7 (because its two's complement value is 256 minus 7, i.e., 249). In one's complement, it represents -6. In sign-magnitude, it would denote -121 (the sign bit is 1, with magnitude 1111001, which is 121).

In computing contexts, this pattern may appear as a byte value. For example, 0xF9 is common in data protocols and can appear in various encodings; as a standalone character, it is not a printable ASCII symbol.

In Unicode/UTF-8, 0xF9 cannot start a valid multi-byte sequence in standard UTF-8. Four-byte sequences use leading bytes in the range 0xF0 to 0xF4; 0xF9 would imply a five-byte sequence, which is not used in modern UTF-8 encoding.

11111001 thus serves as a representative example of how an identical bit pattern can encode different numbers depending on the numeric representation chosen (unsigned, two's complement, one's complement, or sign-magnitude) and how byte values interact with encoding schemes in computing systems.