189 (number)

Last updated
188 189 190
Cardinal one hundred eighty-nine
Ordinal 189th
(one hundred eighty-ninth)
Factorization 33 × 7
Greek numeral ΡΠΘ´
Roman numeral CLXXXIX
Binary 101111012
Ternary 210003
Senary 5136
Octal 2758
Duodecimal 13912
Hexadecimal BD16

189 (one hundred [and] eighty-nine) is the natural number following 188 and preceding 190.

Contents

In mathematics

189 is a centered cube number [1] and a heptagonal number. [2] The centered cube numbers are the sums of two consecutive cubes, and 189 can be written as sum of two cubes in two ways: 43 + 53 and 63 + (3)3. [3] The smallest number that can be written as the sum of two positive cubes in two ways is 1729. [4]

There are 189 zeros among the decimal digits of the positive integers with at most three digits. [5]

The largest prime number that can be represented in 256-bit arithmetic is the "ultra-useful prime" 2256 189, [6] used in quasi-Monte Carlo methods [7] and in some cryptographic systems. [8]

See also

Related Research Articles

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500 is the natural number following 499 and preceding 501.

700 is the natural number following 699 and preceding 701.

600 is the natural number following 599 and preceding 601.

800 is the natural number following 799 and preceding 801.

2000 is a natural number following 1999 and preceding 2001.

3000 is the natural number following 2999 and preceding 3001. It is the smallest number requiring thirteen letters in English.

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<span class="mw-page-title-main">1,000,000</span> Natural number

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<span class="mw-page-title-main">1,000,000,000</span> Natural number

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20,000 is the natural number that comes after 19,999 and before 20,001.

888 is the natural number following 887 and preceding 889.

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References

  1. Sloane, N. J. A. (ed.). "SequenceA005898(Centered cube numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  2. Sloane, N. J. A. (ed.). "SequenceA000566(Heptagonal numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  3. Sloane, N. J. A. (ed.). "SequenceA051347(Numbers that are the sum of two (possibly negative) cubes in at least 2 ways)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  4. Sloane, N. J. A. (ed.). "SequenceA001235(Taxi-cab numbers: sums of 2 cubes in more than 1 way)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  5. Sloane, N. J. A. (ed.). "SequenceA033713(Number of zeros in numbers 1 to 999..9 (n digits))". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  6. Sloane, N. J. A. (ed.). "SequenceA058220(Ultra-useful primes: smallest k such that 2^(2^n) - k is prime)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  7. Hechenleitner, Bernhard; Entacher, Karl (2006). "A parallel search for good lattice points using LLL-spectral tests". Journal of Computational and Applied Mathematics. 189 (1–2): 424–441. doi: 10.1016/j.cam.2005.03.058 . MR   2202988. See Table 5.
  8. Longa, Patrick; Gebotys, Catherine H. (2010). "Efficient Techniques for High-Speed Elliptic Curve Cryptography". In Mangard, Stefan; Standaert, François-Xavier (eds.). Cryptographic Hardware and Embedded Systems, CHES 2010, 12th International Workshop, Santa Barbara, CA, USA, August 17-20, 2010. Proceedings. Lecture Notes in Computer Science. Vol. 6225. Springer. pp. 80–94. doi: 10.1007/978-3-642-15031-9_6 . ISBN   978-3-642-15030-2. See Appendix B.