86

86 is an integer that follows 85 and precedes 87. It is an even composite number, with prime factorization 2 × 43 and divisors 1, 2, 43, and 86.

In numeral representations, 86 is written as 86 in base ten. In other common bases it appears as binary 1010110, octal 126, and hexadecimal 56.

Atomically, 86 is the atomic number of radon, a radioactive noble gas produced by the decay of uranium and thorium. Radon occurs naturally in rocks and soil and can accumulate in buildings, posing health risks due to inhalation, particularly with long-term exposure.

In computing, 86 is associated with the x86 family of processors, derived from the Intel 8086 and widely used since the late 1970s. The term 86 is often used as shorthand for this architecture and its descendants.

In culture and slang, to 86 something means to discard it, refuse service, or otherwise cancel it. The origin of the phrase is debated, but it has become common in American restaurant and retail slang and more broadly.

Notable years related to the number include AD 86 and the year 1986. The latter saw major events such as the Chernobyl disaster and the Space Shuttle Challenger disaster, which had lasting impacts in science, technology, and international policy.