This article may contain excessive, poor, or irrelevant examples. Please improve the article by adding more descriptive text and removing less pertinent examples. See Wikipedia's guide to writing better articles for further suggestions.(March 2010)
In spoken English, the numbers 17 and 70 are sometimes confused because they sound similar. When carefully enunciated, they differ in which syllable is stressed: 17 /sɛvɨnˈtiːn/ vs 70 /ˈsɛvɨnti/. However, in dates such as 1789 or when contrasting numbers in the teens, such as 16, 17, 18, the stress shifts to the first syllable: 17 /ˈsɛvɨntiːn/.
17 is the third Fermat prime, as it is of the form specifically with n = 2, and it is also a Proth prime. Since 17 is a Fermat prime, regular heptadecagons can be constructed with compass and unmarked ruler. This was proven by Carl Friedrich Gauss. Another consequence of 17 being a Fermat prime is that it is not a Higgs prime for squares or cubes; in fact, it is the smallest prime not to be a Higgs prime for squares, and the smallest not to be a Higgs prime for cubes.
Seventeen is the aliquot sum of the semiprime39, and is the aliquot sum of the semiprime 55, and is the base of the 17-aliquot tree.
There are exactly 17 two-dimensional space (plane symmetry) groups. These are sometimes called wallpaper groups, as they represent the seventeen possible symmetry types that can be used for wallpaper.
Like 41, the number 17 is a prime that yields primes in the polynomialn2 + n + p, for all positive n < p − 1.
In the Irregularity of distributions problem, consider a sequence of real numbers between 0 and 1 such that the first two lie in different halves of this interval, the first three in different thirds, and so forth. The maximum possible length of such a sequence is 17 (Berlekamp & Graham, 1970, example 63).
Either 16 or 18 unit squares can be formed into rectangles with perimeter equal to the area; and there are no other natural numbers with this property. The Platonists regarded this as a sign of their peculiar propriety; and Plutarch notes it when writing that the Pythagoreans "utterly abominate" 17, which "bars them off from each other and disjoins them".
17 is the tenth Perrin number, preceded in the sequence by 7, 10, 12.
In base 9, the smallest prime with a composite sum of digits is 17.
17 is known as the Feller number, after the famous mathematician William Feller who taught at Princeton University for many years. Feller would say, when discussing an unsolved mathematical problem, that if it could be proved for the case n = 17 then it could be proved for all positive integers n. He would also say in lectures, "Let's try this for an arbitrary value of n, say n = 17."
Similar to Feller, Prof. Vadim Khayms of Stanford University is also known to use 17 as an arbitrary value during lectures. His Computational Mathematics for Engineers course includes 17 lectures.
17 is the first number that can be written as the sum of a positive cube and a positive square in two different ways; that is, the smallest n such that x3 + y2 = n has two different solutions for x and y positive integers. The next such number is 65.
17 is the minimum number of vertices on a graph such that, if the edges are coloured with 3 different colours, there is bound to be a monochromatic triangle. (See Ramsey's Theorem.)
In 2004, Volatile Films released a feature length film titled The Significance of Seventeen starring Cindy Taylor; one theme addressed by the film is the high incidence of the number 17 and its function as 'the most random number' as described by MIT.
In Halloween H20, Laurie Strode also known as Keri Tate, reveals her true identity to her boyfriend, Will. She tells him that she is related to Michael Myers and mistakenly says that her older sister, Judith Myers, died at the age of 17 years. However, in Halloween (1978), the dates on Judith's tombstone read November 10, 1947 - October 31, 1963. That would have meant that Judith was 15 years old at the time of her death. However, it is probable that the script writers wrote Judith's age as 17 so that it would correspond with Laurie Strodes age from the original film.
The number 17 is a recurring theme in the works of novelistSteven Brust. All of his chaptered novels have either 17 chapters or two books of 17 chapters each. Multiples of 17 frequently appear in his novels set in the fantasy world of Dragaera, where the number is considered holy.
According to Leon Kass, 17 has some significant meaning (as yet not known exactly) in the book of Genesis.
According to Plutarch's Moralia, the Egyptians have a legend that the end of Osiris's life came on the seventeenth of a month, on which day it is quite evident to the eye that the period of the full moon is over. Now, because of this, the Pythagoreans call this day "the Barrier," and utterly abominate this number. For the number seventeen, coming in between the square sixteen and the oblong rectangle eighteen, which, as it happens, are the only plane figures that have their perimeters equal their areas, bars them off from each other and disjoins them, and breaks up the epogdoon by its division into unequal intervals.
From 1987 until 2001, Hendrick Motorsports has used #17 for various drivers in the NASCAR Hall of Fame from 1987-90, and for a satellite team from 1991-92. It was also used by the team owner's son, who died in 2004.
Described at MIT as 'the least random number', according to hackers' lore. This is supposedly because in a study where respondents were asked to choose a random number from 1 to 20, 17 was the most common choice.
This study has been repeated a number of times.
The number of guns in a 17-gun salute to U.S. Army, Air Force and Marine Corps Generals, and Navy and Coast Guard Admirals.
The number of flames emanating from the grenade cap-badge of the Grenadier Guards.
During the Second World War, the four-engined heavy bomber as flown by the USAAF and other Allies and known as "The Flying Fortress", was also known as the B-17.
In Italian culture, the number 17 is considered unlucky. When viewed as the Roman numeral, XVII, it is then changed anagrammatically to VIXI, which in the Latin language it translates to "I have lived", the perfect implying "My life is over." (c.f. "Vixerunt", Cicero's famous announcement of an execution.) Renault sold its "R17" model in Italy as "R177." See Cesana Pariol in the sport section about the name of curve 17.
The fear of the number 17 is called 'heptadecaphobia' or 'heptakaidekaphobia'.
Some species of cicadas have a life cycle of 17 years (i.e. they are buried in the ground for 17 years between every mating season).
The declared percentage alcohol content (by volume) of Baileys Irish Cream - an Irish whiskey and cream based liqueur, made by Gilbeys of Ireland.
^John H. Conway and Richard K. Guy, The Book of Numbers. New York: Copernicus (1996): 11. "Carl Friedrich Gauss (1777–1855) showed that two regular "heptadecagons" (17-sided polygon) could be constructed with ruler and compasses."
^For example, the patriarchJacob lived 17 years years after his son Joseph went missing and presumed dead, and lived 17 years after their reunion in Egypt, and the lifespans of Abraham aged 175, Isaac aged 180, and Jacob aged 147 are not a coincidence. "(The sum of the factors in all three cases is 17; of what possible significance this is, I have no idea.)" Leon Kass, The beginning of wisdom: reading Genesis,(Simon and Schuster, 2003), ISBN 978-0-7432-4299-8, p. 413 n. 10 (citing Genesis 47:28), quote from p. 629 n. 18, found at Google Books. Retrieved June 17, 2009.