| ||||
---|---|---|---|---|
Cardinal | twenty-three | |||
Ordinal | 23rd (twenty-third) | |||
Numeral system | trivigesimal | |||
Factorization | prime | |||
Prime | 9th | |||
Divisors | 1, 23 | |||
Greek numeral | ΚΓ´ | |||
Roman numeral | XXIII | |||
Binary | 101112 | |||
Ternary | 2123 | |||
Senary | 356 | |||
Octal | 278 | |||
Duodecimal | 1B12 | |||
Hexadecimal | 1716 |
23 (twenty-three) is the natural number following 22 and preceding 24.
Twenty-three is the ninth prime number, the smallest odd prime that is not a twin prime. [1] It is, however, a cousin prime with 19, and a sexy prime with 17 and 29; while also being the largest member of the first prime sextuplet (7, 11, 13, 17, 19, 23). [2] Twenty-three is also the next to last member of the first Cunningham chain of the first kind (2, 5, 11, 23, 47), [3] and the sum of the prime factors of the second set of consecutive discrete semiprimes, (21, 22). 23 is the smallest odd prime to be a highly cototient number, as the solution to for the integers 95, 119, 143, and 529. [4]
Hilbert's problems are twenty-three problems in mathematics published by German mathematician David Hilbert in 1900.
The first Mersenne number of the form that does not yield a prime number when inputting a prime exponent is with [30]
On the other hand, the second composite Mersenne number contains an exponent of twenty-three:
The twenty-third prime number (83) is an exponent to the fourteenth composite Mersenne number, which factorizes into two prime numbers, the largest of which is twenty-three digits long when written in base ten: [31] [32]
Further down in this sequence, the seventeenth and eighteenth composite Mersenne numbers have two prime factors each as well, where the largest of these are respectively twenty-two and twenty-four digits long,
Where prime exponents for and add to 106, which lies in between prime exponents of and , the index of the latter two (17 and 18) in the sequence of Mersenne numbers sum to 35, which is the twenty-third composite number. [33]
is twenty-three digits long in decimal, and there are only three other numbers whose factorials generate numbers that are digits long in base ten: 1, 22, and 24.
The Leech lattice Λ24 is a 24-dimensional lattice through which 23 other positive definite even unimodular Niemeier lattices of rank 24 are built, and vice-versa. Λ24 represents the solution to the kissing number in 24 dimensions as the precise lattice structure for the maximum number of spheres that can fill 24-dimensional space without overlapping, equal to 196,560 spheres. These 23 Niemeier lattices are located at deep holes of radii √2 in lattice points around its automorphism group, Conway group . The Leech lattice can be constructed in various ways, which include:
Conway and Sloane provided constructions of the Leech lattice from all other 23 Niemeier lattices. [34]
Twenty-three four-dimensional crystal families exist within the classification of space groups. These are accompanied by six enantiomorphic forms, maximizing the total count to twenty-nine crystal families. [35] Five cubes can be arranged to form twenty-three free pentacubes, or twenty-nine distinct one-sided pentacubes (with reflections). [36] [37]
There are 23 three-dimensional uniform polyhedra that are cell facets inside uniform 4-polytopes that are not part of infinite families of antiprismatic prisms and duoprisms: the five Platonic solids, the thirteen Archimedean solids, and five semiregular prisms (the triangular, pentagonal, hexagonal, octagonal, and decagonal prisms).
23 Coxeter groups of paracompact hyperbolic honeycombs in the third dimension generate 151 unique Wythoffian constructions of paracompact honeycombs. 23 four-dimensional Euclidean honeycombs are generated from the cubic group, and 23 five-dimensional uniform polytopes are generated from the demihypercubic group.
In two-dimensional geometry, the regular 23-sided icositrigon is the first regular polygon that is not constructible with a compass and straight edge or with the aide of an angle trisector (since it is neither a Fermat prime nor a Pierpont prime), nor by neusis or a double-notched straight edge. [38] It is also not constructible with origami, however it is through other traditional methods for all regular polygons. [39]
19 (nineteen) is the natural number following 18 and preceding 20. It is a prime number.
21 (twenty-one) is the natural number following 20 and preceding 22.
70 (seventy) is the natural number following 69 and preceding 71.
90 (ninety) is the natural number following 89 and preceding 91.
25 (twenty-five) is the natural number following 24 and preceding 26.
72 (seventy-two) is the natural number following 71 and preceding 73. It is half a gross or six dozen.
84 (eighty-four) is the natural number following 83 and preceding 85. It is seven dozens.
64
31 (thirty-one) is the natural number following 30 and preceding 32. It is a prime number.
58 (fifty-eight) is the natural number following 57 and preceding 59.
61 (sixty-one) is the natural number following 60 and preceding 62.
63 (sixty-three) is the natural number following 62 and preceding 64.
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.
360 is the natural number following 359 and preceding 361.
127 is the natural number following 126 and preceding 128. It is also a prime number.
500 is the natural number following 499 and preceding 501.
600 is the natural number following 599 and preceding 601.
168 is the natural number following 167 and preceding 169.
271 is the natural number after 270 and before 272.
14 (fourteen) is the natural number following 13 and preceding 15.
{{cite book}}
: |work=
ignored (help)