14 (number)

14 (fourteen) is the natural number following 13 and preceding 15.

More specifically, it is the first member of the second cluster of two discrete semiprimes (14, 15); the next such cluster is (21, 22), members whose sum is the fourteenth prime number, 43.

A set of real numbers to which it is applied closure and complement operations in any possible sequence generates 14 distinct sets.

[6] This holds even if the reals are replaced by a more general topological space; see Kuratowski's closure-complement problem.

[7] 14 is the number of equilateral triangles that are formed by the sides and diagonals of a regular six-sided hexagon.

[8] In a hexagonal lattice, 14 is also the number of fixed two-dimensional triangular-celled polyiamonds with four cells.

[9] 14 is the number of elements in a regular heptagon (where there are seven vertices and edges), and the total number of diagonals between all its vertices.

[10][11] The Klein quartic is a compact Riemann surface of genus 3 that has the largest possible automorphism group order of its kind (of order 168) whose fundamental domain is a regular hyperbolic 14-sided tetradecagon, with an area of

Several distinguished polyhedra in three dimensions contain fourteen faces or vertices as facets: A regular tetrahedron cell, the simplest uniform polyhedron and Platonic solid, is made up of a total of 14 elements: 4 edges, 6 vertices, and 4 faces.

14 is also the root (non-unitary) trivial stella octangula number, where two self-dual tetrahedra are represented through figurate numbers, while also being the first non-trivial square pyramidal number (after 5);[18][19] the simplest of the ninety-two Johnson solids is the square pyramid

[a] There are a total of fourteen semi-regular polyhedra, when the pseudorhombicuboctahedron is included as a non-vertex transitive Archimedean solid (a lower class of polyhedra that follow the five Platonic solids).

[20][21][b] Fourteen possible Bravais lattices exist that fill three-dimensional space.

, and holds a compact form homeomorphic to the zero divisors with entries of unit norm in the sedenions,

[23][24] The floor of the imaginary part of the first non-trivial zero in the Riemann zeta function is

[citation needed] There is a fourteen-point silver star marking the traditional spot of Jesus’ birth in the Basilica of the Nativity in Bethlehem.

According to the genealogy of Jesus in the Gospel of Matthew, “…there were fourteen generations in all from Abraham to David, fourteen generations from David to the exile to Babylon, and fourteen from the exile to the Messiah” (Matthew 1:17).

The fundamental domain of the Klein quartic is a regular hyperbolic 14-sided tetradecagon , with an area of .