86 (number)

86 is the natural number following 85 and preceding 87.

In mathematics

86 is:

nontotient and a noncototient.
the 25th distinct semiprime and the 13th of the form.
together with 85 and 87, forms the middle semiprime in the 2nd cluster of three consecutive semiprimes; the first comprising 33, 34, 35.
an Erdős–Woods number, since it is possible to find sequences of 86 consecutive integers such that each inner member shares a factor with either the first or the last member.
a happy number and a self number in base 10.
with an aliquot sum of 46; itself a semiprime, within an aliquot sequence of seven members in the Prime 3-aliquot tree.

It appears in the Padovan sequence, preceded by the terms 37, 49, 65.
It is conjectured that 86 is the largest n for which the decimal expansion of 2ⁿ contains no 0.
86 = + +. That is, 86 is equal to the sum of the numbers formed in calculating its multiplicative persistence.

In American English, and particularly in the food service industry, 86 has become a slang term referring to an item being out of stock or discontinued, and by extension to a person no longer welcome on the premises.
86, particularly "Hachi-Roku," is often used in Japan as the nickname for the Toyota AE86.
The international calling code for Mainland China
86 is the racing number of Chick Hicks — a character from Disney Pixar's Cars franchise.