20 (number)

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192021
Cardinaltwenty
Ordinal20th
(twentieth)
Factorization22· 5
Divisors1, 2, 4, 5, 10, 20
Roman numeralXX
Binary101002
Ternary2023
Quaternary1104
Quinary405
Senary326
Octal248
Duodecimal1812
Hexadecimal1416
Vigesimal1020
Base 36K36
 
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For other uses, see 20 (disambiguation).
192021
Cardinaltwenty
Ordinal20th
(twentieth)
Factorization22· 5
Divisors1, 2, 4, 5, 10, 20
Roman numeralXX
Binary101002
Ternary2023
Quaternary1104
Quinary405
Senary326
Octal248
Duodecimal1812
Hexadecimal1416
Vigesimal1020
Base 36K36

20 (twenty) is the natural number following 19 and preceding 21. A group of twenty units may also be referred to as a score.[1]

In mathematics[edit]

An icosahedron has 20 faces

In science[edit]

Biology[edit]

As an indefinite number[edit]

In sports[edit]

A standard dartboard is laid out as 20 sectors

Age 20[edit]

In other fields[edit]

References[edit]

  1. ^ John H. Conway and Richard K. Guy, The Book of Numbers. New York: Copernicus (1996): 11. ""Score" is related to "share" and comes from the Old Norse "skor" meaning a "notch" or "tally" on a stick used for counting. ... Often people counted in 20s; every 20th notch was larger, and so "score" also came to mean 20."
  2. ^ Sequence A131646 in The On-Line Encyclopedia of Integer Sequences
  3. ^ "Biblical Criticism", The Classical Journal 36:71:83ff (March 1827) full text
  4. ^ "CBS News", Scores of Typhoon Survivors Flown to Manila (November 2013) [1]