285 (number)

285 is the natural number following 284 and preceding 286.

In mathematics

 * 285 is an odd composite number.
 * 285 is the 9th square pyramidal number. That means it is the sum of a number of consecutive perfect squares starting with 1. For 285, it is the sum of all of the single digits' perfect squares.
 * 285 is the number of variations possible with a binary rooted tree with 13 points. A binary rooted tree means that it always begins with 1 point that is rooted. From there, each point can branch in up to two directions.
 * 285 is a sphenic number which means that it has three prime factors.
 * 285 is a Harshad number. That means that it is divisible by the sum of its digits. 285 is divisible by 15.
 * 285 is a repdigit number in base 7. In base 7, 285 is 555.
 * 285 is a very symmetric number. If flipped horizontally, these numbers are symmetrical.

In technology

 * The Turbojet 285 is a variation of the Williams Jet Tenders motorboat that is smaller than its other designs. It is designed for personal use.
 * In North America, the area code 285 does not exist. If you are receiving a call from a number that begins with 285, it is likely a spam call.

World Records

 * On December 9, 2022, Peter Thomson received the Guinness World Record for the greatest number of crossovers while jumping rope in a row.
 * On October 7, 2015, Camelot UK Lotteries Limited achieved the Guinness World Record for the longest champagne cork popping relay.
 * The Guinness World Record for the greatest number of people in an online video toast chain as of December 16, 2022, is 285. It was achieved in Cereser, Brazil.
 * On April 12, 2018, the Narraghmore Vintage Club received the Guinness World Record for having the largest parade of 285 tractors

Other fields

 * The calendar years 285 AD and 285 BC.
 * In the French Republican calendar, The year 285 would be a year 9 cycle and be in 2077.
 * 285 Regina is a Main belt asteroid that was discovered in 1889 by Auguste Charlois in Nice, France.
 * In 1980 the 285th Civil Engineering Squadron in the United States Air Force. It is located on the US Virgin Islands.
 * 285 is the number for several highways in Brazil, Canada, Ireland, Japan, and the United States
 * Interstate Highway 285 in Georgia is listed as one of the most dangerous highways in the United States with 3.5 deaths per 10 miles per year.