220 (number)
Encyclopedia : 2 : 22 : 220 : 220 (number)
220 (two hundred [and] twenty) is the natural number following 219 and preceding 221.
| |
| Ordinal | two hundred twenty |
| Cardinal | two hundred twentieth |
| Factorization | [220 = 2^2 \cdot 5 \cdot 11] |
| Roman numeral | CCXX |
| Binary | 11011100 |
| Hexadecimal | DC |
Mathematics
It is a composite number, with its divisors being 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110, making it an amicable number with 284. 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.
Other fields
220 is:- A common voltage in the United States and Canada.
- In the Holy 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).
- The designation of some spur routes of U.S. Interstate 20.
- The year A.D. 220 or 220 BC.
Reference
- Wells, D. (1987). The Penguin Dictionary of Curious and Interesting Numbers (pp. 145 - 147). London: Penguin Group.
221-229
Two hundred twenty-one has its own article.
Two hundred twenty-two 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
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
Two hundred twenty-six 226 = 2·113, centered pentagonal number.
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).
Two hundred twenty-nine 229 prime, twin prime with 227
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