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1289 (number)
The number 1289 (twelve hundred eighty-nine) is the natural number following 1288 and preceding 1290. "Number Gossip: 1289", March 2008, webpage: Numbergossip-1289 In mathematics The number 1289 is an odd prime number, following 1283 and preceding 1291. It is classified as an apocalyptic power, a deficient number, and an evil number: * The number 1289 is called an apocalyptic power because 21289 contains the consecutive digits 666 (in decimal), as the Number of the beast: in the sequence ..., 1281, 1285, 1286, 1289, 1290, 1298, 1301, etc. "Apocalyptic Number -- from Wolfram MathWorld", Mathworld.Wolfram.com, August 2010, webpage: MW-Apoc * The number 1289 is a deficient number because the sum of all its positive divisors (except itself) totals less than 1289. Compare with perfect and abundant numbers. * The number 1289 is an evil number because it has an even number of 1's contained in its binary expansion. In technology * 1289 is a 4.5 volt battery Battery mos ... [...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] |
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] |
Deficient Number
In number theory, a deficient number or defective number is a number ''n'' for which the sum of divisors of ''n'' is less than 2''n''. Equivalently, it is a number for which the sum of proper divisors (or aliquot sum) is less than ''n''. For example, the proper divisors of 8 are 1, 2, and 4, and their sum is less than 8, so 8 is deficient. Denoting by ''σ''(''n'') the sum of divisors, the value 2''n'' − ''σ''(''n'') is called the number's deficiency. In terms of the aliquot sum ''s''(''n''), the deficiency is ''n'' − ''s''(''n''). Examples The first few deficient numbers are :1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 22, 23, 25, 26, 27, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, ... As an example, consider the number 21. Its divisors are 1, 3, 7 and 21, and their sum is 32. Because 32 is less than 42, the number 21 is deficient. Its deficiency is 2 × 21 − 32 = 10. Properties Since the aliquot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evil Number
In number theory, an evil number is a non-negative integer that has an even Hamming weight, number of 1s in its Binary number, binary expansion. These numbers give the positions of the zero values in the Thue–Morse sequence, and for this reason they have also been called the Thue–Morse set. Non-negative integers that are not evil are called odious numbers. Examples The first evil numbers are: :0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39 ... Equal sums The partition of the non-negative integers into the odious and evil numbers is the unique partition of these numbers into two sets that have equal multisets of pairwise sums. As 19th-century mathematician Eugène Prouhet showed, the partition into evil and odious numbers of the numbers from 0 to 2^k-1, for any k, provides a solution to the Prouhet–Tarry–Escott problem of finding sets of numbers whose sums of powers are equal up to the kth power. In computer science In computer science, an evil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Number Of The Beast
The number of the beast ( grc-koi, Ἀριθμὸς τοῦ θηρίου, ) is associated with the Beast of Revelation in chapter 13, verse 18 of the Book of Revelation. In most manuscripts of the New Testament and in English translations of the Bible, the number of the beast is six hundred sixty-six or (in Greek numerals, represents 600, represents 60 and represents 6). Papyrus 115 (which is the oldest preserved manuscript of the ''Revelation'' ), as well as other ancient sources like ''Codex Ephraemi Rescriptus'', give the number of the beast as χιϛ or χιϲ, transliterable in Arabic numerals as 616 (), not 666; critical editions of the Greek text, such as the '' Novum Testamentum Graece'', note χιϛ as a variant. In the Bible χξϛ The number of the beast is described in Revelation 13:15–18. Several translations have been interpreted for the meaning of the phrase "Here is Wisdom. Let him that hath understanding count the number of the beast..." where the pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfect Number
In number theory, a perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. For instance, 6 has divisors 1, 2 and 3 (excluding itself), and 1 + 2 + 3 = 6, so 6 is a perfect number. The sum of divisors of a number, excluding the number itself, is called its aliquot sum, so a perfect number is one that is equal to its aliquot sum. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors including itself; in symbols, \sigma_1(n)=2n where \sigma_1 is the sum-of-divisors function. For instance, 28 is perfect as 1 + 2 + 4 + 7 + 14 = 28. This definition is ancient, appearing as early as Euclid's ''Elements'' (VII.22) where it is called (''perfect'', ''ideal'', or ''complete number''). Euclid also proved a formation rule (IX.36) whereby q(q+1)/2 is an even perfect number whenever q is a prime of the form 2^p-1 for positive integer p—what is now called a Mersenne prime. Two millennia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abundant Number
In number theory, an abundant number or excessive number is a number for which the sum of its proper divisors is greater than the number. The integer 12 is the first abundant number. Its proper divisors are 1, 2, 3, 4 and 6 for a total of 16. The amount by which the sum exceeds the number is the abundance. The number 12 has an abundance of 4, for example. Definition A number ''n'' for which the ''sum'' ''of'' ''divisors'' ''σ''(''n'') > 2''n'', or, equivalently, the sum of proper divisors (or aliquot sum) ''s''(''n'') > ''n''. Abundance is the value ''σ''(''n'') − ''2n'' (or ''s''(''n'') − ''n''). Examples The first 28 abundant numbers are: :12, 18, 20, 24, 30, 36, 40, 42, 48, 54, 56, 60, 66, 70, 72, 78, 80, 84, 88, 90, 96, 100, 102, 104, 108, 112, 114, 120, ... . For example, the proper divisors of 24 are 1, 2, 3, 4, 6, 8, and 12, whose sum is 36. Because 36 is greater than 24, the number 24 is abundant. Its abundance is 36 − 24 = 12. Prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery (electricity)
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1289
Year 1289 ( MCCLXXXIX) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. Events By place Europe * June 11 – Battle of Campaldino: Pro-papal Guelph forces of Florence and their allies, Lucca, Pistoia, Prato and Siena under Vicount Aimery IV defeat the Ghibelline army (some 10,000 men) in Tuscany. Florence becomes the dominant power in Central Italy, powerful merchant guilds take on a more political role in the communal government against their rivals of Genoa, Pisa and Venice. * July 7 – Battle of Copenhagen: A Norwegian expeditionary force under King Eric II, supported by Danish outlaws, sets sail to Copenhagen and attacks the city. But they are repelled and forced to withdraw to Zealand. England * Summer – King Edward I (Longshanks) proposes a marriage between his infant son, Edward of Caernarfon, and the 6-year-old Margaret (Maid of Norway). * Construction of Conwy Castle in Wales, ord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1289 BC
The 1280s BC was a decade which lasted from 1289 BC to 1280 BC. {{Decadebox BC, 128 Events and trends *1290 BC—Seti I becomes pharaoh of Egypt. During his reign he leads his armies into Asia, asserting Egyptian imperial authority. Seti recaptures the traitorous vassals of Kadesh and Amurru, and even defeats a Hittite force. Later, he is unable to maintain control over the territories in the Levant and eventually concludes peace with the Hittite king Muwatalli II. *c. 1285 BC—Judgement of Hunefer before Osiris, illustration from a Book of the Dead is painted (Nineteenth dynasty of Egypt, 19th Dynasty). It is now in the British Museum at London. *1282 BC—Pandion II, legendary King of Athens, dies after a nominal reign of 25 years. He reportedly only reigned in Megara, while Athens and the rest of Attica, Greece, Attica were under the control of an alliance of Nobles led by his uncle Metion (son of Erechtheus II, Erechtheus of Athens) and his sons (including in some accounts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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