Home > 17 (number)

1 In mathematics

Seventeen is the 7th smallest prime number, and is a Fermat prime. The next prime is nineteen, with which it comprises a twin prime. 17 is the sum of the first four primes. 17 is the sixth Mersenne prime exponent, yielding 131071.

There are exactly seventeen two-dimensional space (plane symmetry) groups. These are sometimes called wallpaper groupPlane crystallographic groups or wallpaper groups There are seventeen different types of wallpaper patterns. As opposed to the frieze patterns, these patterns cover the entire plane and can be extended infinitely in any direction on the plane. Discrete frs, as they represent the seventeen possible symmetry types that can be used for wallpaper.

Like 41Integers 41 is the natural number following 40 and preceding 42. Cardinal forty-one Ordinal41st(forty-first) Factorization''prime Roman numeralXLI Binary101001 Hexadecimal29 Forty-one is the 13th smallest prime number. The next is forty-three, with which, the number 17 is a prime that yields primes in the polynomial n² + n + p, for all positive n < p - 1.

Consider a sequence of real numberIn mathematics, the real numbers are intuitively defined as numbers that are in one-to-one correspondence with the points on an infinite line—the number line. The term "real number" is a retronym coined in response to " imaginary number". Real numbers mays between 0 and 1 such that the first two lie in different halves of this intervalTopology In elementary algebra, an interval is a set that contains every real number between two indicated numbers, and possibly the two numbers themselves. Interval notation is where the permitted values for a variable are expressed as ranging over an in, the first three in different thirds, and so forth. The maximum possible length of such a sequence is 17 (Berlekamp & Graham, 1970, example 63).

Since 17 is a Fermat prime, heptadecagons can be drawn with compass and ruler. This was proved by Karl Friedrich Gauss.

2 In Science

• The atomic numberThe atomic number Z is a term used in chemistry and physics to represent the number of protons found in the nucleus of an atom. In an atom of neutral charge, the number of electrons typically equals the atomic number. The atomic number originally meant th of chlorineChlorine (from Gr. Chloros meaning "pale green"), is the chemical element with atomic number 17 and symbol Cl . It is a halogen, found in the periodic table in group 17. Chlorine gas is greenish yellow, is two and one half times as heavy as air, has an in.
• The Brodmann areaA Brodmann area is a region in the brain cortex defined by its cytoarchitectonic characteristics. Brodmann areas were originally defined by Korbinian Brodmann and referred to by numbers from 1 to 52. Some of the original areas have been subdivided further defining the primary visual processing area of mammallian brains.