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100,000,000
100,000,000 (one hundred million) is the natural number following 99,999,999 and preceding 100,000,001. In scientific notation, it is written as 108. East Asian languages treat 100,000,000 as a counting unit, significant as the square of a myriad, also a counting unit. In Chinese, Korean, and Japanese respectively it is ''yi'' () (or in ancient texts), ''eok'' () and ''oku'' (). These languages do not have single words for a thousand to the second, third, fifth powers, etc. 100,000,000 is also the fourth power of 100 and also the square of 10000. Selected 9-digit numbers (100,000,001–999,999,999) 100,000,001 to 199,999,999 * 100,000,007 = smallest nine digit prime * 100,005,153 = smallest triangular number with 9 digits and the 14,142nd triangular number * 100,020,001 = 100012, palindromic square * 100,544,625 = 4653, the smallest 9-digit cube * 102,030,201 = 101012, palindromic square * 102,334,155 = Fibonacci number * 102,400,000 = 405 * 104,060,401 = 102012 = 1014, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
10000
10,000 (ten thousand) is the natural number following 9,999 and preceding 10,001. Name Many languages have a specific word for this number: in Ancient Greek it is (the etymological root of the word myriad in English), in Aramaic , in Hebrew [], in Chinese language, Chinese (Mandarin , Cantonese , Hokkien ''bān''), in Japanese language, Japanese [], in Khmer language, Khmer [], in Korean language, Korean [], in Russian language, Russian [], in Vietnamese language, Vietnamese , in Sanskrit अयुत [''ayuta''], in Thai language, Thai [], in Malayalam [], and in Malagasy language, Malagasy ''alina''. In many of these languages, it often denotes a very large but indefinite number. The classical Greeks used letters of the Greek alphabet to represent Greek numerals: they used a capital letter mu (Μ) to represent ten thousand. This Greek root was used in early versions of the metric system in the form of the decimal prefix myria-. The number ten thousand can also b ... [...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 numbers'', and numbers used for ordering are called '' 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 jersey numbers). Some definitions, including the standard 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 numbers form a set. Many other number sets are built by suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motzkin Number
In mathematics, the th Motzkin number is the number of different ways of drawing non-intersecting chords between points on a circle (not necessarily touching every point by a chord). The Motzkin numbers are named after Theodore Motzkin and have diverse applications in geometry, combinatorics and number theory. The Motzkin numbers M_n for n = 0, 1, \dots form the sequence: : 1, 1, 2, 4, 9, 21, 51, 127, 323, 835, 2188, 5798, 15511, 41835, 113634, 310572, 853467, 2356779, 6536382, 18199284, 50852019, 142547559, 400763223, 1129760415, 3192727797, 9043402501, 25669818476, 73007772802, 208023278209, 593742784829, ... Examples The following figure shows the 9 ways to draw non-intersecting chords between 4 points on a circle (): : The following figure shows the 21 ways to draw non-intersecting chords between 5 points on a circle (): : Properties The Motzkin numbers satisfy the recurrence relations :M_=M_+\sum_^M_iM_=\fracM_+\fracM_. The Motzkin numbers can be express ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Highly Composite Number
In mathematics, a superior highly composite number is a natural number which has the highest ratio of its number of divisors to ''some'' positive power of itself than any other number. It is a stronger restriction than that of a highly composite number, which is defined as having more divisors than any smaller positive integer. The first 10 superior highly composite numbers and their factorization are listed. For a superior highly composite number ''n'' there exists a positive real number ''ε'' such that for all natural numbers ''k'' smaller than ''n'' we have :\frac\geq\frac and for all natural numbers ''k'' larger than ''n'' we have :\frac>\frac where ''d(n)'', the divisor function, denotes the number of divisors of ''n''. The term was coined by Ramanujan (1915). For example, the number with the most divisors per square root of the number itself is 12; this can be demonstrated using some highly composites near 12. \frac\approx 1.414, \frac=1.5, \frac\approx 1.633, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-descriptive Number
In mathematics, a self-descriptive number is an integer ''m'' that in a given base ''b'' is ''b'' digits long in which each digit ''d'' at position ''n'' (the most significant digit being at position 0 and the least significant at position ''b''−1) counts how many instances of digit ''n'' are in ''m''. Example For example, in base 10, the number 6210001000 is self-descriptive because of the following reasons: In base 10, the number has 10 digits, indicating its base; It contains 6 at position 0, indicating that there are six 0s in 6210001000; It contains 2 at position 1, indicating that there are two 1s in 6210001000; It contains 1 at position 2, indicating that there is one 2 in 6210001000; It contains 0 at position 3, indicating that there is no 3 in 6210001000; It contains 0 at position 4, indicating that there is no 4 in 6210001000; It contains 0 at position 5, indicating that there is no 5 in 6210001000; It contains 1 at position 6, indicating that there is one 6 in 62100 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pell Number
In mathematics, the Pell numbers are an infinite sequence of integers, known since ancient times, that comprise the denominators of the closest rational approximations to the square root of 2. This sequence of approximations begins , , , , and , so the sequence of Pell numbers begins with 1, 2, 5, 12, and 29. The numerators of the same sequence of approximations are half the companion Pell numbers or Pell–Lucas numbers; these numbers form a second infinite sequence that begins with 2, 6, 14, 34, and 82. Both the Pell numbers and the companion Pell numbers may be calculated by means of a recurrence relation similar to that for the Fibonacci numbers, and both sequences of numbers grow exponentially, proportionally to powers of the silver ratio 1 + . As well as being used to approximate the square root of two, Pell numbers can be used to find square triangular numbers, to construct integer approximations to the right isosceles triangle, and to solve certain comb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primorial
In mathematics, and more particularly in number theory, primorial, denoted by "#", is a function from natural numbers to natural numbers similar to the factorial function, but rather than successively multiplying positive integers, the function only multiplies prime numbers. The name "primorial", coined by Harvey Dubner, draws an analogy to ''primes'' similar to the way the name "factorial" relates to ''factors''. Definition for prime numbers For the th prime number , the primorial is defined as the product of the first primes: :p_n\# = \prod_^n p_k, where is the th prime number. For instance, signifies the product of the first 5 primes: :p_5\# = 2 \times 3 \times 5 \times 7 \times 11 = 2310. The first five primorials are: : 2, 6, 30, 210, 2310 . The sequence also includes as empty product. Asymptotically, primorials grow according to: :p_n\# = e^, where is Little O notation. Definition for natural numbers In general, for a positive integer , its p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prime Numbers
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 alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safe Prime
In number theory, a prime number ''p'' is a if 2''p'' + 1 is also prime. The number 2''p'' + 1 associated with a Sophie Germain prime is called a . For example, 11 is a Sophie Germain prime and 2 × 11 + 1 = 23 is its associated safe prime. Sophie Germain primes are named after French mathematician Sophie Germain, who used them in her investigations of Fermat's Last Theorem. One attempt by Germain to prove Fermat’s Last Theorem was to let ''p'' be a prime number of the form 8''k'' + 7 and to let ''n'' = ''p'' – 1. In this case, x^n + y^n = z^n is unsolvable. Germain’s proof, however, remained unfinished. Through her attempts to solve Fermat's Last Theorem, Germain developed a result now known as Germain's Theorem which states that if ''p'' is an odd prime and 2''p'' + 1 is also prime, then ''p'' must divide ''x'', ''y'', or ''z.'' Otherwise, x^n + y^n \neq z^n. This case where ''p'' does not divide ''x'', ''y'', or ''z'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repdigit
In recreational mathematics, a repdigit or sometimes monodigit is a natural number composed of repeated instances of the same digit in a positional number system (often implicitly decimal). The word is a portmanteau of repeated and digit. Examples are 11, 666, 4444, and 999999. All repdigits are palindromic numbers and are multiples of repunits. Other well-known repdigits include the repunit primes and in particular the Mersenne primes (which are repdigits when represented in binary). Repdigits are the representation in base B of the number x\frac where 0 1 and ''n'', ''m'' > 2 : **(''p'', ''x'', ''y'', ''m'', ''n'') = (31, 5, 2, 3, 5) corresponding to 31 = 111112 = 1115, and, **(''p'', ''x'', ''y'', ''m'', ''n'') = (8191, 90, 2, 3, 13) corresponding to 8191 = 11111111111112 = 11190, with 11111111111 is the repunit with thirteen digits 1. *For each sequence o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automorphic Number
In mathematics, an automorphic number (sometimes referred to as a circular number) is a natural number in a given number base b whose square "ends" in the same digits as the number itself. Definition and properties Given a number base b, a natural number n with k digits is an automorphic number if n is a fixed point of the polynomial function f(x) = x^2 over \mathbb/b^k\mathbb, the ring of integers modulo b^k. As the inverse limit of \mathbb/b^k\mathbb is \mathbb_b, the ring of b-adic integers, automorphic numbers are used to find the numerical representations of the fixed points of f(x) = x^2 over \mathbb_b. For example, with b = 10, there are four 10-adic fixed points of f(x) = x^2, the last 10 digits of which are one of these : \ldots 0000000000 : \ldots 0000000001 : \ldots 8212890625 : \ldots 1787109376 Thus, the automorphic numbers in base 10 are 0, 1, 5, 6, 25, 76, 376, 625, 9376, 90625, 109376, 890625, 2890625, 7109376, 12890625, 87109376, 212890625, 787109376, 178 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A000957
A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, " a", and its variant " an", are indefinite articles. History The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish it fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
