220 (number)

220 (two hundred [and] twenty) is the natural number following 219 and preceding 221.

← 200 210 220 230 240 250 260 270 280 290 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred twenty
Ordinal	two hundred twentieth
Factorization	$220 = 2^2 \cdot 5 \cdot 11$
Roman numeral	CCXX
Binary	11011100
Hexadecimal	DC

Contents

1 In mathematics
2 In other fields
3 221-229
4 Notes
5 References

In mathematics

It is a composite number, with its divisors being 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110, making it an amicable number with 284.^[1]^[2] Also, being divisible by the sum of its digits, 220 is a Harshad number.

It is the sum of four consecutive primes (47 + 53 + 59 + 61).

It is a tetrahedral number, the sum of the first ten triangular numbers.

In other fields

The number 220 can also refer to:

The years 220 AD and 220 BC.
A common voltage in many countries.
An SMTP code meaning "service ready"
A series of garden tractors produced by Case (and later by Case IH) in the 1970s and 1980s - the series included the 220(10HP), the 222(12HP) and the 224(14HP).
A film format for medium format cameras (see 120 film).
A single by music duo t.A.T.u.
An album by guitarist Phil Keaggy.
The InterCity 225 train, a newer version of the InterCity 125.

221-229

Two hundred [and] twenty-one has its own article.

Two hundred [and] twenty-two has its own article.

Two hundred [and] twenty-three has its own article.

Two hundred [and] twenty-four 224 = 2⁵·7

224 is the sum of 2 cubes:

224 = 2³ + 6³

224 is the sum of the cubes of 4 consecutive integers:

224 = 2³ + 3³ + 4³ + 5³

224 is a Harshad number.

See also: Area code 224

Two hundred [and] twenty-five 225 = 3²·5² = 15²

225 is the sum of the cubes of the first five integers:

225 = 1³ + 2³ + 3³ + 4³ + 5³

225 is the sum of 3 cubes:

225 = 1³ + 2³ + 6³

225 is a refactorable number, an octagonal number, a centered octagonal number, and a Harshad number.

225 is the only 3-digit square with all prime digits.

See also: Area code 225 - North American telephone area code 225 encompasses a section of south Louisiana, including Baton Rouge. The area code has come to be part of the identity of the Baton Rouge area to the extent that there is a local news magazine named 225.

Two hundred [and] twenty-six 226 = 2·113

226 is a centered pentagonal number.

See also: Area code 226

Two hundred [and] twenty-seven has its own article.

Two hundred [and] twenty-eight 228 = 2²·3·19

228 is the sum of six consecutive primes (29 + 31 + 37 + 41 + 43 + 47), the sum of ten consecutive primes (7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 + 41), a refactorable number, a Harshad number, and a repdigit in base 7 (444).

See also:

Two hundred [and] twenty-nine has its own article.

Notes

^ Bryan Bunch, The Kingdom of Infinite Number. New York: W. H. Freeman & Company (2000): 167
^ Higgins, Peter (2008). Number Story: From Counting to Cryptography. New York: Copernicus. p. 61. ISBN 978-1-84800-000-1.

References

Wells, D. (1987). The Penguin Dictionary of Curious and Interesting Numbers (pp. 145 - 147). London: Penguin Group.