A polygon with 12 sides is called a dodecagon.
A polyhedron with 12 faces is called a dodecahedron, in which a regular dodecahedron is one of the five regular polyhedrons.
12 is the number of kisses in three-dimensional space.
In the problem of ball installation in three-dimensional Euclidean space, if the unit ball is tangent to the unit ball, 12 balls can be put in (Kepler conjecture).
In polyhedron, 12 is the number of edges of cubes and octahedrons, and also the number of vertices of icosahedron, truncated semi-cube and truncated tetrahedron.
Fifth highest composite number
The factors of the sixth composite number are: 1, 2, 3, 4, 6, 12.
Pell number
The first remainder (because the sum of other divisors except itself is16 >; 12)
The first semi-perfect number: 2+4+6= 12.
The sum of the Pythagorean numbers of the first group (the circumference of the Egyptian triangle: 3:4:5)
The third pentagonal number and tangible number
The fourth Pronik number
The smallest number n is equal to n and n! It can be expressed as the product of multiple prime factorials (12 = 2! 3! 12! = 2! 3! 1 1! )
A unique number makes n 1, n/2 1 and n/3 1 all prime numbers.
The third super factorial is the product of the first three factorials.
The cardinal number of decimal notation. Decimalization is considered to be a relatively simple way to express shares with decimals, but it is not used in daily life calculation.
In the notation based on 13 or above (such as hexadecimal, etc. ), 12 is marked with the Latin letter C.
The factor of the sum of any pair of twin prime numbers (except the first pair).
The number of positive factors of 12 (6) is a perfect number, and the sum of all its positive factors is also a perfect number (1+2+3+4+6+ 12=28). Only two figures of this nature have been found for the time being.
Multiplication formula: three, four, twelve, two, six, twelve.
Seek adoption