285 (number)

From HandWiki
Short description: Natural number
← 284 285 286 →
Cardinaltwo hundred eighty-five
Ordinal285th
(two hundred eighty-fifth)
Factorization3 × 5 × 19
Divisors1, 3, 5, 15, 19, 57, 95, 285
Greek numeralΣΠΕ´
Roman numeralCCLXXXV
Binary1000111012
Ternary1011203
Quaternary101314
Quinary21205
Senary11536
Octal4358
Duodecimal1B912
Hexadecimal11D16
VigesimalE520
Base 367X36

285 is the natural number following 284 and preceding 286.

In mathematics

  • 285 is an odd composite number.[1]
  • 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.[2]
  • 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.[3]
  • 285 is a sphenic number which means that it has three prime factors.[4]
  • 285 is a Harshad number. That means that it is divisible by the sum of its digits. 285 is divisible by 15.[5]
  • 285 is a repdigit number in base 7. In base 7, 285 is 555.[6]
  • 285 is a very symmetric number. If flipped horizontally, these numbers are symmetrical.[7]

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.[8]
  • 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.[9]

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.[10]
  • On October 7, 2015, Camelot UK Lotteries Limited achieved the Guinness World Record for the longest champagne cork popping relay.[11]
  • 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 Brazil .[12]
  • On April 12, 2018, the Narraghmore Vintage Club received the Guinness World Record for having the largest parade of 285 tractors

Other fields

References

  1. "Composite numbers". https://mathworld.wolfram.com/CompositeNumber.html. 
  2. "Square pyramidal number sequence". https://mathworld.wolfram.com/SquarePyramidalNumber.html. 
  3. "Binary rooted tree". https://mathworld.wolfram.com/RootedTree.html. 
  4. "Sphenic numbers". https://mathworld.wolfram.com/SphenicNumber.html. 
  5. "Harshad numbers". https://mathworld.wolfram.com/HarshadNumber.html. 
  6. "Repdigit numbers". https://mathworld.wolfram.com/Repdigit.html. 
  7. Sloane, N. J. A., ed. "Sequence A053701 (Vertically symmetric numbers)". OEIS Foundation. https://oeis.org/A053701. 
  8. "Turbojet 285 Williams Jet Tenders motorboat". https://www.williamsjettenders.com/owners-centre/turbojet-285/. 
  9. "Area code 285". https://www.areacodehelp.com/where/area_code_285.shtml. 
  10. "Guinness World Record 285 crossovers whil jumping rope". https://www.guinnessworldrecords.com/world-records/547163-most-consecutive-double-under-crossovers-criss-cross-while-skipping. 
  11. "Cork popping relay record". https://www.guinnessworldrecords.com/world-records/391004-longest-champagne-cork-popping-relay. 
  12. "285 people in a video toast chain". https://www.guinnessworldrecords.com/world-records/115753-most-people-in-an-online-video-toast-chain. 
  13. "French Republican Calendar Guide". https://broadcast.lds.org/elearning/FHD/Community/en/FamilySearch/Handwriting/French/Lesson2/Handouts/French_Republican_Calendar.pdf. 
  14. "285 Regina". https://in-the-sky.org/data/object.php?id=A285. 
  15. "285th Civil Engineering Squadron". https://vi.ng.mil/VI-Air-Guard/285th-CES-ANG/. 
  16. "Interstate 285 is the most dangerous highway in the United States". https://www.schollelaw.com/auto-accidents/the-dangers-of-atlanta-i-285-accidents.