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Nonagonal Number
A nonagonal number, or an enneagonal number, is a figurate number that extends the concept of triangular number, triangular and square numbers to the nonagon (a nine-sided polygon). However, unlike the triangular and square numbers, the patterns involved in the construction of nonagonal numbers are not rotationally symmetrical. Specifically, the ''n''th nonagonal number counts the dots in a pattern of ''n'' nested nonagons, all sharing a common corner, where the ''i''th nonagon in the pattern has sides made of ''i'' dots spaced one unit apart from each other. The nonagonal number for ''n'' is given by the formula: :\frac . Nonagonal numbers The first few nonagonal numbers are: :0 (number), 0, 1 (number), 1, 9 (number), 9, 24 (number), 24, 46 (number), 46, 75 (number), 75, 111 (number), 111, 154 (number), 154, 204 (number), 204, 261 (number), 261, 325 (number), 325, 396 (number), 396, 474 (number), 474, 559 (number), 559, 651 (number), 651, 750 (number), 750, 856 (number), 856, 96 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figurate Number
The term figurate number is used by different writers for members of different sets of numbers, generalizing from triangular numbers to different shapes (polygonal numbers) and different dimensions (polyhedral numbers). The ancient Greek mathematicians already considered triangular numbers, polygonal numbers, tetrahedral numbers, and pyramidal numbers, ReprintedG. E. Stechert & Co., 1934 and AMS Chelsea Publishing, 1944. and subsequent mathematicians have included other classes of these numbers including numbers defined from other types of polyhedra and from their analogs in other dimensions. Terminology Some kinds of figurate number were discussed in the 16th and 17th centuries under the name "figural number". In historical works about Greek mathematics the preferred term used to be ''figured number''. In a use going back to Jacob Bernoulli's Ars Conjectandi, the term ''figurate number'' is used for triangular numbers made up of successive integers, tetrahedral numbers made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
559 (number)
500 (five hundred) is the natural number following 499 and preceding 501. Mathematical properties 500 = 22 × 53. It is an Achilles number and a Harshad number, meaning it is divisible by the sum of its digits. It is the number of planar partitions of 10. Other fields Five hundred is also *the number that many NASCAR races often use at the end of their race names (e.g., Daytona 500), to denote the length of the race (in miles, kilometers or laps). *the longest advertised distance (in miles) of the IndyCar Series and its premier race, the Indianapolis 500. Slang names * Monkey (UK slang for £500; US slang for $500) Integers from 501 to 599 500s 501 501 = 3 × 167. It is: * the sum of the first 18 primes (a term of the sequence ). * palindromic in bases 9 (6169) and 20 (15120). 502 * 502 = 2 × 251 * vertically symmetric number 503 503 is: * a prime number. * a safe prime. * the sum of three consecutive primes (163 + 167 + 17 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5500
5000 (five thousand) is the natural number following 4999 and preceding 5001. Five thousand is, at the same time, the largest Heterogram (literature), isogrammic numeral, and the smallest number that contains every one of the five vowels (a, e, i, o, u) in certain dialects of the English language (i.e. those that do not include the word “and” when writing out 230, 250, 260, 602, and 640). Selected numbers in the range 5001–5999 5001 to 5099 * 5003 – Sophie Germain prime * 5020 – amicable number with 5564 * 5021 – super-prime, twin prime with 5023 * 5023 – twin prime with 5021 * 5039 – factorial prime, Sophie Germain prime * 5040 (number), 5040 = 7!, superior highly composite number * 5041 = 712, centered octagonal number * 5050 – triangular number, Kaprekar number, sum of first 100 integers * 5051 – Sophie Germain prime * 5059 – super-prime * 5076 – decagonal number * 5077 – prime of the form 2p-1 * 5081 – Sophie Germain prime * 5087 – safe prime * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4200
4000 (four thousand) is the natural number following 3999 and preceding 4001. It is a decagonal number. Selected numbers in the range 4001–4999 4001 to 4099 * 4005 – triangular number * 4007 – safe prime * 4010 – magic constant of ''n'' × ''n'' normal magic square and ''n''-queens problem for ''n'' = 20 * 4013 – balanced prime * 4019 – Sophie Germain prime * 4021 – prime of the form 2p-1 * 4027 – super-prime * 4028 – sum of the first 45 primes * 4030 – third weird number * 4031 – sum of the cubes of the first six primes * 4032 – pronic number * 4033 – sixth super-Poulet number; strong pseudoprime in base 2 * 4057 – prime of the form 2p-1 * 4060 – tetrahedral number * 4073 – Sophie Germain prime * 4079 – safe prime * 4091 – super-prime * 4095 – triangular number and odd abundant number; number of divisors in the sum of the fifth and largest known unitary perfect number, largest Ramanujan–Nagell number of the form 2^ - 1 * 4096 = 642 = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1956 (number)
1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000. A group of one thousand units is sometimes known, from Ancient Greek, as a chiliad. A period of one thousand years may be known as a chiliad or, more often from Latin, as a millennium. The number 1000 is also sometimes described as a short thousand in medieval contexts where it is necessary to distinguish the Germanic concept of 1200 as a long thousand. It is the first 4-digit integer. Notation * The decimal representation for one thousand is ** 1000—a one followed by three zeros, in the general notation; ** 1 × 103—in engineering notation, which for this number coincides with: ** 1 × 103 exactly—in scientific normalized exponential notation; ** 1 E+3 exactly—in scientific E notation. * The SI prefix for a thousand units is "kilo-", abbreviated t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1089 (number)
1089 is the integer after 1088 and before 1090. It is a square number (33 squared), a nonagonal number, a 32-gonal number, a 364-gonal number, and a centered octagonal number. 1089 is the first reverse-divisible number. The next is 2178 , and they are the only four-digit numbers that divide their reverse. In magic 1089 is widely used in magic tricks because it can be "produced" from any two three-digit numbers. This allows it to be used as the basis for a Magician's Choice. For instance, one variation of the book test starts by having the spectator choose any two suitable numbers and then apply some basic maths to produce a single four-digit number. That number is always 1089. The spectator is then asked to turn to page 108 of a book and read the 9th word, which the magician has memorized. To the audience it looks like the number is random, but through manipulation, the result is always the same. In base 10, the following steps always yield 1089: # Take any three-digit num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
969 (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" telephone calls in the North American Numbering Plan (900 number) * 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, 42nd triangular number, Schröder–Hipparchus number, Mertens function(903) returns 0, little Schr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
