257 (number)

Last updated
← 256 257 258 →
Cardinal two hundred fifty-seven
Ordinal 257th
(two hundred fifty-seventh)
Factorization prime
Prime yes
Greek numeral ΣΝΖ´
Roman numeral CCLVII
Binary 1000000012
Ternary 1001123
Senary 11056
Octal 4018
Duodecimal 19512
Hexadecimal 10116

257 (two hundred [and] fifty-seven) is the natural number following 256 and preceding 258.

257 is a prime number of the form specifically with n = 3, and therefore a Fermat prime. Thus a regular polygon with 257 sides is constructible with compass and unmarked straightedge. It is currently the second largest known Fermat prime. [1]

Analogously, 257 is the third Sierpinski prime of the first kind, of the form ➜ . [2]

It is also a balanced prime, [3] an irregular prime, [4] a prime that is one more than a square, [5] and a Jacobsthal–Lucas number. [6]

There are exactly 257 combinatorially distinct convex polyhedra with eight vertices (or polyhedral graphs with eight nodes). [7]

Related Research Articles

17 (seventeen) is the natural number following 16 and preceding 18. It is a prime number.

73 (seventy-three) is the natural number following 72 and preceding 74. In English, it is the smallest natural number with twelve letters in its spelled out name.

57 (fifty-seven) is the natural number following 56 and preceding 58.

68 (sixty-eight) is the natural number following 67 and preceding 69. It is an even number.

103 is the natural number following 102 and preceding 104.

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.

300 is the natural number following 299 and preceding 301.

400 is the natural number following 399 and preceding 401.

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.

900 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.

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

1,000,000,000 is the natural number following 999,999,999 and preceding 1,000,000,001. With a number, "billion" can be abbreviated as b, bil or bn.

233 is the natural number following 232 and preceding 234.

171 is the natural number following 170 and preceding 172.

353 is the natural number following 352 and preceding 354. It is a prime number.

5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. It has garnered attention throughout history in part because distal extremities in humans typically contain five digits.

60,000 (sixty thousand) is the natural number that comes after 59,999 and before 60,001. It is a round number. It is the value of (F25).

In mathematics, the Jacobsthal numbers are an integer sequence named after the German mathematician Ernst Jacobsthal. Like the related Fibonacci numbers, they are a specific type of Lucas sequence for which P = 1, and Q = −2—and are defined by a similar recurrence relation: in simple terms, the sequence starts with 0 and 1, then each following number is found by adding the number before it to twice the number before that. The first Jacobsthal numbers are:

References

  1. ↑ Hsiung, C. Y. (1995), Elementary Theory of Numbers, Allied Publishers, pp. 39–40, ISBN   9788170234647 .
  2. ↑ Weisstein, Eric W. "Sierpiński Number of the First Kind". mathworld.wolfram.com. Retrieved 2020-07-30.
  3. ↑ Sloane, N. J. A. (ed.). "SequenceA006562(Balanced primes)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  4. ↑ Sloane, N. J. A. (ed.). "SequenceA000928(Irregular primes)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  5. ↑ Sloane, N. J. A. (ed.). "SequenceA002496(Primes of form n^2 + 1)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  6. ↑ Sloane, N. J. A. (ed.). "SequenceA014551(Jacobsthal-Lucas numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  7. ↑ Sloane, N. J. A. (ed.). "SequenceA000944(Number of polyhedra (or 3-connected simple planar graphs) with n nodes)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.