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
Roman numeral	CCXX
Binary	11011100
Hexadecimal	DC

[edit] 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] 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.

[edit] In other fields

The number 220 can also refer to:

• The year 220 AD or 220 BC.
• A common voltage in many countries.
• In the Bible, the number of goats Jacob gave to his brother Esau ("two hundred she-goats and twenty he-goats") and the number of sheep ("two hundred ewes and twenty rams," Genesis 32:14).
• An SMTP code meaning "service ready"
• A film format for medium format cameras (see 120 film).
• 220 (t.A.T.u. song), a single by music duo t.A.T.u..
• An album by guitarist Phil Keaggy.

[edit] 221-229

Two hundred twenty-one has its own article.

Two hundred twenty-two has its own article.

Two hundred twenty-three has its own article.

Two hundred twenty-three 223 prime, sum of three consecutive primes (71 + 73 + 79), sum of seven consecutive primes (19 + 23 + 29 + 31 + 37 + 41 + 43), smallest number requiring 37 fifth powers for Waring representation (see Waring's problem), strictly non-palindromic number; also the number of United Nations resolution 223, regarding the treatment of Israel, and the flight number of a British Airways plane believed targeted for the symbolism of its number

Two hundred twenty-four 224 = 2⁵·7, Harshad number, Zuckerman number

Two hundred twenty-five 225 = 3²·5² = 15², refactorable number, octagonal number, centered octagonal number, sum of the cubes of the first five integers, Harshad number, number of squares on a Scrabble board.

Two hundred twenty-six 226 = 2·113, centered pentagonal number.

Two hundred twenty-seven has its own article.

Two hundred twenty-seven 227 prime, safe prime, twin prime with 229, Chen prime, Eisenstein prime with no imaginary part, also the name of a TV show starring Marla Gibbs and Hal Williams

Two hundred twenty-eight 228 = 2²·3·19, sum of six consecutive primes (29 + 31 + 37 + 41 + 43 + 47), sum of ten consecutive primes (7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 + 41), refactorable number, Harshad number, repdigit in base 7 (444).

See also: 228 Incident

Two hundred twenty-nine has its own article.

Two hundred twenty-nine 229 prime, twin prime with 227

[edit] Notes

1. ^ Bryan Bunch, The Kingdom of Infinite Number. New York: W. H. Freeman & Company (2000): 167

[edit] References

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