|This article does not cite any references or sources. (December 2009)|
|Cardinal||two hundred forty|
(two hundred and fortieth)
|Factorization||24× 3 × 5|
With 20 divisors total (1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120, and 240), more than any previous number, 240 is a highly composite number, and it is also a refactorable number or tau number, since it has 20 divisors and 20 divides 240. And since it has 31 totient answers, more than any previous integer, 240 is a highly totient number.
240 is a semiperfect number.
240 can be expressed as a sum of consecutive primes in two different ways: 240 = 53 + 59 + 61 + 67 = 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43. It can also be expressed as the product of two consecutive integers, 15 and 16, thus 240 is a pronic number.
Also, being divisible by the sum of its digits, 240 is a Harshad number, and not only that, it is also a concatenation of two of its proper divisors (see Sloane's A50480).
E8 has 240 roots.
There are 240 distinct solutions of the Soma cube puzzle.
In other fields
- A common voltage in England and Australia before conversion to 230V standard.
- In pre-decimal British currency, the number of pence in a pound until 1971.
- A cholesterol level of 240 and above is considered high risk.
- The model number of the Convair 240.
- The year A.D. 240 or 240 BC.
- Datsun 240Z
- Mercedes 240D
- Nissan 240SX
- Volvo 240
- An area code overlay of the 301 area code in western Maryland.
- The famous skit by the sketch comedy group The State is entitled "$240 Worth of Pudding"
241 - 249
241 has its own article.
242 has its own article.
243 has its own article.
244 has its own article..
- Dialing code for Angola.
245 has its own article.
- Dialing code for Guinea-Bissau
246 has its own article.
Two hundred [and] forty-seven 247 = 13·19, pentagonal number.
247 = 50123 - 49876, and is the smallest number which can be expressed as the difference between two integers such that together, they contain all digits 0-9.
- Sometimes (when it is a URL, etc.) may use "247" as an alternate to 24/7, it is an abbreviation which stands for "24 hours a day, 7 days a week".
- Approximate number of acres in a square kilometer.
- The number 248 is also the Gematria value for the Hebrew letters Ramach (Resh Mem and Het), traditionally depicted as the number of organs in the human body, and the number of positive commandments in the Torah.
Two hundred [and] forty-nine 249 = 3·83, Blum integer