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971 (number)
971 (nine hundred seventy one) is the natural number following 970 and preceding 972. 971 is a prime number, an emirp, a Chen prime and an Eisenstein prime. Some uses of 971: *+971, the country calling code for telephone numbers in the United Arab Emirates * Area code 971, for telephone numbers in northwestern Oregon *One of the ISBN identifier groups for books published in the Philippines U.S. state highways As a U.S. state route or highway, 971 may refer to: *Louisiana Highway 971 *Washington State Route 971 *West Virginia Route 971 External links 971at Wolfram Alpha WolframAlpha ( ) is an answer engine developed by Wolfram Research. It answers factual queries by computing answers from externally sourced data. WolframAlpha was released on May 18, 2009 and is based on Wolfram's earlier product Wolfram Mat ... Integers {{Num-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country"). Numbers used for counting are called ''Cardinal number, cardinal numbers'', and numbers used for ordering are called ''Ordinal number, ordinal numbers''. Natural numbers are sometimes used as labels, known as ''nominal numbers'', having none of the properties of numbers in a mathematical sense (e.g. sports Number (sports), jersey numbers). Some definitions, including the standard ISO/IEC 80000, ISO 80000-2, begin the natural numbers with , corresponding to the non-negative integers , whereas others start with , corresponding to the positive integers Texts that exclude zero from the natural numbers sometimes refer to the natural numbers together with zero as the whole numbers, while in other writings, that term is used instead for the integers (including negative integers). The natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
970 (number)
900 (nine hundred) is the natural number following 899 and preceding 901. It is the square of 30 and the sum of Euler's totient function for the first 54 positive integers. In base 10 it is a Harshad number. It is also the first number to be the square of a sphenic number. In other fields 900 is also: * A telephone area code for "premium" phone calls in the North American Numbering Plan * In Greek number symbols, the sign Sampi ("ϡ", literally "like a pi") * A skateboarding trick in which the skateboarder spins two and a half times (360 degrees times 2.5 is 900) * A 900 series refers to three consecutive perfect games in bowling * Yoda's age in Star Wars Integers from 901 to 999 900s * 901 = 17 × 53, centered triangular number, happy number * 902 = 2 × 11 × 41, sphenic number, nontotient, Harshad number * 903 = 3 × 7 × 43, sphenic number, triangular number, Schröder–Hipparchus number, Mertens function (903) returns 0, little Schroeder number * 904 = 23 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
972 (number)
900 (nine hundred) is the natural number following 899 and preceding 901. It is the square of 30 and the sum of Euler's totient function for the first 54 positive integers. In base 10 it is a Harshad number. It is also the first number to be the square of a sphenic number. In other fields 900 is also: * A telephone area code for "premium" phone calls in the North American Numbering Plan * In Greek number symbols, the sign Sampi ("ϡ", literally "like a pi") * A skateboarding trick in which the skateboarder spins two and a half times (360 degrees times 2.5 is 900) * A 900 series refers to three consecutive perfect games in bowling * Yoda's age in Star Wars Integers from 901 to 999 900s * 901 = 17 × 53, centered triangular number, happy number * 902 = 2 × 11 × 41, sphenic number, nontotient, Harshad number * 903 = 3 × 7 × 43, sphenic number, triangular number, Schröder–Hipparchus number, Mertens function (903) returns 0, little Schroeder number * 904 = 23 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prime Number
A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, or , involve 5 itself. However, 4 is composite because it is a product (2 × 2) in which both numbers are smaller than 4. Primes are central in number theory because of the fundamental theorem of arithmetic: every natural number greater than 1 is either a prime itself or can be factorized as a product of primes that is unique up to their order. The property of being prime is called primality. A simple but slow method of checking the primality of a given number n, called trial division, tests whether n is a multiple of any integer between 2 and \sqrt. Faster algorithms include the Miller–Rabin primality test, which is fast but has a small chance of error, and the AKS primality test, which always pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emirp
An emirp (''prime'' spelled backwards) is a prime number that results in a different prime when its decimal digits are reversed. This definition excludes the related palindromic primes. The term ''reversible prime'' is used to mean the same as emirp, but may also, ambiguously, include the palindromic primes. The sequence of emirps begins 13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, 167, 179, 199, 311, 337, 347, 359, 389, 701, 709, 733, 739, 743, 751, 761, 769, 907, 937, 941, 953, 967, 971, 983, 991, ... . All non-palindromic permutable primes are emirps. , the largest known emirp is 1010006+941992101×104999+1, found by Jens Kruse Andersen in October 2007. The term 'emirpimes' (singular) is used also in places to treat semiprimes in a similar way. That is, an emirpimes is a semiprime that is also a (distinct) semiprime upon reversing its digits. It is an open problem whether there are infinitely many emirps. Other bases The emirps in base 12 are (using rotated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chen Prime
A prime number ''p'' is called a Chen prime if ''p'' + 2 is either a prime or a product of two primes (also called a semiprime). The even number 2''p'' + 2 therefore satisfies Chen's theorem. The Chen primes are named after Chen Jingrun, who proved in 1966 that there are infinitely many such primes. This result would also follow from the truth of the twin prime conjecture as the lower member of a pair of twin primes is by definition a Chen prime. The first few Chen primes are : 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 47, 53, 59, 67, 71, 83, 89, 101, … . The first few Chen primes that are not the lower member of a pair of twin primes are :2, 7, 13, 19, 23, 31, 37, 47, 53, 67, 83, 89, 109, 113, 127, ... . The first few non-Chen primes are :43, 61, 73, 79, 97, 103, 151, 163, 173, 193, 223, 229, 241, … . All of the supersingular primes are Chen primes. Rudolf Ondrejka discovered the following 3 × 3 magic square of n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eisenstein Prime
In mathematics, an Eisenstein prime is an Eisenstein integer : z = a + b\,\omega, \quad \text \quad \omega = e^, that is irreducible (or equivalently prime) in the ring-theoretic sense: its only Eisenstein divisors are the units , itself and its associates. The associates (unit multiples) and the complex conjugate of any Eisenstein prime are also prime. Characterization An Eisenstein integer is an Eisenstein prime if and only if either of the following (mutually exclusive) conditions hold: # is equal to the product of a unit and a natural prime of the form (necessarily congruent to ), # is a natural prime (necessarily congruent to 0 or ). It follows that the square of the absolute value of every Eisenstein prime is a natural prime or the square of a natural prime. In base 12 (written with digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, , ): The natural Eisenstein primes are exactly the natural primes ending with 5 or (i.e. the natural primes congruent to ). (The natural primes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Numbers In The United Arab Emirates
Telephone numbers in the United Arab Emirates (UAE) follow a closed telephone numbering plan. The UAE is assigned an international dialing code of +971 by ITU-T. Telephone numbers are fixed at seven digits, with area codes fixed at two or three digits. Area Codes Before 2000 Subscriber numbers were 5- or 6- digits, with area code plus subscriber number totalling 7 digits. Current The overall structure of the UAE's national numbering plan is: Landline numbers begin with: *01 Al Karama (Canceled) *02 Abu Dhabi *03 Al Ain *04 Dubai *06 Sharjah, Ajman and Umm al-Quwain *07 Ras Al Khaimah *08 Western Region (Liwa, etc.) *09 Fujairah Mobile numbers begin with: *050 cell phones (Etisalat) *052 cell phones ( Du) *054 cell phones (Etisalat) ''(Recently released for public use.)'' *055 cell phones ( Du) *056 cell phones (Etisalat) *058 cell phones ( Du/Virgin Mobile) ''(Recently released for public use.)'' 057: call phones: DOMC Emergency Numbers The following numbers are used for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 971
Area codes 503 and 971 are telephone area codes in the North American Numbering Plan (NANP) for the northwestern region of the U.S. state of Oregon. The numbering plan area (NPA) comprises the cities of Portland, Salem, and Astoria. Area code 503 was one of the original North American area codes of 1947, assigned to the entire state until 1995, when its extent was reduced to the northwest corner. Area code 971 was assigned to the service area in stages, completed in 2008, to form an overlay in the area with ten-digit dialing. History In the initial configuration of the nationwide telephone numbering plan designed by AT&T in 1947, the state of Oregon was assigned a single area code, 503. Despite Oregon's growth in the second half of the twentieth century, particularly in the Willamette Valley (Portland and Eugene), this remained so for 48 years, making Oregon one of the largest states by area with a single area code. By the early 1990s, the proliferation of cell phones and pagers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of ISBN Identifier Groups
The registration group or identifier group is the second element in a 13-digit ISBN (first element in a 10-digit ISBN) and indicates the country, geographic region, or language area where a book was published. The element ranges from one to five numerical digits. In 2007, the length of an ISBN changed from 10 to 13 digits, and a new 3-digit prefix (978 or 979) was added in front of 10-digit ISBNs. The following registration groups are compatible with or without a 978- prefix: * 0–5, 7 * 600–649 * 80–94 * 950–989 * 9900–9989 * 99900–99999 The following must have a 979- prefix: * 979-8 * 979-10 through 979-12 *(979-0 is reserved for International Standard Music Numbers for sheet music) Shorter registration group numbers are generally used for countries or regions with greater publishing volume. Because a longer number leaves room for fewer publishers and ISBNs, several countries have more than one number assigned. On the other hand, some countries (Australia, Switze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisiana Highway 971
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bordered by the state of Texas to the west, Arkansas to the north, Mississippi to the east, and the Gulf of Mexico to the south. A large part of its eastern boundary is demarcated by the Mississippi River. Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska and its boroughs). The state's capital is Baton Rouge, and its largest city is New Orleans, with a population of roughly 383,000 people. Some Louisiana urban environments have a multicultural, multilingual heritage, being so strongly influenced by a mixture of 18th century Louisiana French, Dominican Creole, Spanish, French Canadian, Acadia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washington State Route 971
State Route 971 (SR 971) is a state highway in the U.S. state of Washington. It runs for and primarily serves Lake Chelan State Park, with both of its termini at U.S. Route 97 Alternate (US 97A) southwest of Chelan. SR 971 has the highest highway number in the state. The highway traverses Navarre Coulee along the route of a 19th-century road that was later connected to Chelan in the 1910s. Both roads were paved in the 1960s and incorporated into SR 971 when it was established by the state legislature in 1991. Route description SR 971 begins at a junction with US 97A on the Columbia River near the former town of Winesap, approximately north of Entiat. The highway travels northwest along Ficher Canyon and turns north to follow Navarre Coulee, which cuts through an arm of the Chelan Mountains at the eastern end of the Okanogan–Wenatchee National Forest and near the Chelan State Wildlife Area. After passing several small farms, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
