In all Germanic languages, 13 is the first compound number the numbers 11 and 12 have their own names.List of basic calculations Multiplication There are 13 architectonic honeycombs: 8 originate from the C ~ 3 that are closed under union and intersection.Some also include the Elongated square gyrobicupola as another Archimedean solid. There are 13 Archimedean solids without counting enantiomorphic forms.There are 13 distinct cubic distance-regular graphs, of which the Platonic Tetrahedral graph and Dodecahedral graph are part.There are 13 hexagonal isohedral tilings.A 13-sided regular polygon is called a tridecagon.Since 5 2 + 12 2 = 13 2, (5, 12, 13) forms a Pythagorean triple, and as such represent the sides of a right triangle.There are 13 different ways for the three fastest horses in a horse race to finish, allowing for ties, a fact that can be expressed mathematically by 13 being the third ordered Bell number.The sum and the difference of 2 consecutive squares: 13 = (2 2 + 3 2) = (7 2 - 6 2).The smallest number whose fourth power can be written as a sum of two consecutive square numbers (119 2 + 120 2).A Fibonacci number, preceded by 5 and 8.It is the second Wilson prime, of three known (the others being 5 and 563), and the smallest emirp in decimal. It is a twin prime with 11, as well as a cousin prime with 17. This can be witnessed, for example, in the "Twelve Days of Christmas" of Western European tradition. Strikingly folkloric aspects of the number 13 have been noted in various cultures around the world: one theory is that this is due to the cultures employing lunar-solar calendars (there are approximately 12.41 lunations per solar year, and hence 12 "true months" plus a smaller, and often portentous, thirteenth month).
13 ( thirteen) is the natural number following 12 and preceding 14.
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