216 (عدد)
| ||||
---|---|---|---|---|
كمي | صفر | |||
ترتيبي | 216 (صفر) | |||
التحليل لعوامل | 23× 33 | |||
القواسم | 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 108, 216 | |||
العدد اليوناني | ΣΙϚ´ | |||
العدد الروماني | CCXVI | |||
ثنائي | 110110002 | |||
ثلاثي | 220003 | |||
رباعي | 31204 | |||
خماسي | 13315 | |||
سداسي | 10006 | |||
ثماني | 3308 | |||
اثنا عشري | 16012 | |||
ستة عشري | D816 | |||
عشريني | AG20 | |||
أساس 36 | 6036 |
216 (مئتان وستة عشر) هو عدد طبيعي يلي 215 ويسبق 217. وهو مكعب، وكثيراً ما يُدعى عدد أفلاطون، بالرغم من أنه من غير المؤكد أنه هو العدد الذي كان يقصده أفلاطون.
في الرياضيات
216 is the cube of 6, and the sum of three cubes:
It is the smallest cube that can be represented as a sum of three positive cubes,[1] making it the first nontrivial example for Euler's sum of powers conjecture. It is, moreover, the smallest number that can be represented as a sum of any number of distinct positive cubes in more than one way.[2] It is a highly powerful number: the product
of the exponents in its prime factorization
is larger than the product of exponents of any smaller number.[3]
Because there is no way to express it as the sum of the proper divisors of any other integer, it is an عدد غير ملموس.[4] Although it is not a semiprime, the three closest numbers on either side of it are, making it the middle number between twin semiprime-triples, the smallest number with this property.[5] Sun Zhiwei has conjectured that each natural number not equal to 216 can be written as either a triangular number or as a triangular number plus a prime number; however, this is not possible for 216. If the conjecture is true, 216 would be the only number for which this is not possible.[6]
There are 216 ordered pairs of four-element permutations whose products generate all the other permutations on four elements.[7] There are also 216 fixed hexominoes, the polyominoes made from 6 squares, joined edge-to-edge. Here "fixed" means that rotations or mirror reflections of hexominoes are considered to be distinct shapes.[8]
في المجالات الأخرى
216 هو أحد التفاسير الشائعة لـ عدد أفلاطون، الذي وصفه أفلاطون بتعبيرات غامضة في الجمهورية. Other interpretations include 3600 and 12960000.[9]
There are 216 colors in the web-safe color palette, a color cube.[10]
The international calling code for Tunisia
انظر أيضاً
المراجع
- ^ Sloane, N. J. A. (ed.). "Sequence A066890 (Cubes that are the sum of three distinct positive cubes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A003998 (Numbers that are a sum of distinct positive cubes in more than one way)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A005934 (Highly powerful numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A005114 (Untouchable numbers, also called nonaliquot numbers: impossible values for the sum of aliquot parts function)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A202319 (Lesser of two semiprimes sandwiched each between semiprimes thus forming a twin semiprime-triple)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sun, Zhi-Wei (2009). "On sums of primes and triangular numbers". Journal of Combinatorics and Number Theory. 1 (1): 65–76. arXiv:0803.3737. MR 2681507.
- ^ Sloane, N. J. A. (ed.). "Sequence A071605 (Number of ordered pairs (a,b) of elements of the symmetric group S_n such that the pair a,b generates S_n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A001168 (Number of fixed polyominoes with n cells)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Adam, J. (February 1902). "The arithmetical solution of Plato's number". The Classical Review. 16 (1): 17–23. doi:10.1017/S0009840X0020526X. JSTOR 694295. S2CID 161664478.
- ^ Thomas, B. (1998). "Palette's plunder". IEEE Internet Computing. 2 (2): 87–89. doi:10.1109/4236.670691.