222 (number)

222 (two hundred [and] twenty-two) is the natural number following 221 and preceding 223.

It is a decimal repdigit^[1] and a strobogrammatic number (meaning that it looks the same turned upside down on a calculator display).^[2] It is one of the numbers whose digit sum in decimal is the same as it is in binary.^[3]

222 is a noncototient, meaning that it cannot be written in the form n − φ(n) where φ is Euler's totient function counting the number of values that are smaller than n and relatively prime to it.^[4]

There are exactly 222 distinct ways of assigning a meet and join operation to a set of ten unlabeled elements in order to give them the structure of a lattice,^[5] and exactly 222 different six-edge polysticks.^[6]

See also

• The years CE 222 or 222 BCE.
• Room 222 (TV show)
• Bell 222 (helicopter)
• SdKfz 222, a World War II German reconnaissance vehicle
• The 222s, a Montreal punk band which took its name from a code name for co-codaprin
• 222, a comedy album by Patton Oswalt
• "222", a song by Paul McCartney on the 2-CD edition of his 2007 studio album Memory Almost Full.
• A-222 Bereg, a Russian self-propelled 130 mm coastal defence gun
• .222 Remington and .222 Remington Magnum, firearm cartridges

References