254

254 is the natural number that follows 253 and precedes 255. In mathematics, it is an even composite number with the prime factorization 2 × 127, making it a semiprime. Its positive divisors are 1, 2, 127, and 254. In various numeral systems, 254 is written as 11111110 in binary, 376 in octal, and FE in hexadecimal. In Roman numerals, it is written as CCLIV.

As 254 is 2 less than 256, it has applications and occurrences related to eight-bit computing and digital encoding. In 8-bit byte terminology, 254 is the value 0xFE. In many extended character encodings such as ISO/IEC 8859-1 and Windows-1252, decimal 254 maps to a non-ASCII character, with the exact glyph depending on the code page.

In science and engineering, 254 nanometers is a prominent wavelength in the ultraviolet C (UV-C) range produced by mercury lamps. The UV-C line at 254 nm is widely used for germicidal disinfection of air, water, and surfaces due to its effectiveness in inactivating microorganisms such as bacteria and viruses.

Geography and telecommunications use the number in different contexts. The international country calling code +254 is assigned to Kenya, used when dialing Kenyan telephone numbers from abroad.

Overall, 254 is notable for its mathematical properties as a semiprime, its binary and hex representations, its relation to eight-bit computing, its role in UV-C disinfection, and its designation as Kenya’s international dialing code.