426

426 is a natural number that follows 425 and precedes 427. In mathematics, 426 is even and composite, with prime factorization 2 × 3 × 71. Its positive divisors are 1, 2, 3, 6, 71, 142, 213, and 426. The sum of its proper divisors is 438, making 426 an abundant number. It has eight divisors in total.

In base representations, 426 is 0x1AA in hexadecimal, 0b110101010 in binary, and 0o652 in octal. In Roman numerals it is written as CDXXVI.

In science and technology, 426 nanometers lies in the blue‑violet portion of the visible spectrum. In computing and networking contexts, 426 is used as an HTTP status code meaning Upgrade Required, indicating that the client must switch to a different protocol.

As a calendar designation, 426 can denote a year in the common era (426 CE) or in the years before the common era (426 BCE), each belonging to different historical contexts and events documented in corresponding historical records.

Overall, 426 is notable for its mathematical properties as a small abundant number and for its various representations across numeral systems, as well as for its occasional use in science, technology, and chronology.