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19th Military Zone
19 (nineteen) is the natural number following 18 (number), 18 and preceding 20 (number), 20. It is a prime number. Mathematics 19 is the eighth prime number, and forms a sexy prime with 13 (number), 13, a twin prime with 17 (number), 17, and a cousin prime with 23 (number), 23. It is the third full reptend prime, the fifth Trinomial triangle#Central trinomial coefficients, central trinomial coefficient, and the seventh Mersenne prime exponent. It is also the second Keith number, and more specifically the first Keith prime. * 19 is the maximum number of fourth powers needed to sum up to any natural number, and in the context of Waring's problem, 19 is the fourth value of Waring's problem#The number g(k), g(k). * The sum of the squares of the first 19 primes is divisible by 19. *19 is the sixth Heegner number. 67 (number), 67 and 163 (number), 163, respectively the 19th and 38th prime numbers, are the two largest Heegner numbers, of 9, nine total. * 19 is the third centered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonadecimal
There are many different numeral systems, that is, writing systems for expressing numbers. By culture / time period By type of notation Numeral systems are classified here as to whether they use positional notation (also known as place-value notation), and further categorized by radix or base. Standard positional numeral systems The common names are derived Hexadecimal#Etymology, somewhat arbitrarily from a mix of Latin and Greek language, Greek, in some cases including roots from both languages within a single name. There have been some proposals for standardisation. Non-standard positional numeral systems Bijective numeration Signed-digit representation Negative bases The common names of the negative base numeral systems are formed using the prefix ''nega-'', giving names such as: Complex-base system, Complex bases Non-integer representation, Non-integer bases p-adic number, ''n''-adic number Mixed radix * Factorial number system * Even double factorial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
