29 (number)

29 (twenty-nine) is the natural number following 28 and preceding 30.

In mathematics

It is the tenth prime number, and also the fourth primorial prime. It forms a twin prime pair with thirty-one, which is also a primorial prime. Twenty-nine is also the sixth Sophie Germain prime. It is also the sum of three consecutive squares, 2² + 3² + 4². It is a Lucas prime, a Pell prime, and a tetranacci number. It is an Eisenstein prime with no imaginary part and real part of the form $3n-1$ . Since 18! + 1 is a multiple of 29 but 29 is not one more than a multiple 18, 29 is a Pillai prime. 29 is also the 10th supersingular prime.

None of the first 29 natural numbers have more than two different prime factors. This is the longest such consecutive sequence.

Twenty-nine is the aliquot sum of the odd discrete biprimes 115 and 187 and is the base of the 29-aliquot tree.

29 is a Markov number, appearing in the solutions to $x^{2}+y^{2}+z^{2}=3xyz$ : {2, 5, 29}, {2, 29, 169}, {5, 29, 433}, {29, 169, 14701}, etc.

29 is a Perrin number, preceded in the sequence by 12, 17, 22.

Since the greatest prime factor of 29² + 1 = 842 is 421, which is obviously more than 29 twice, 29 is a Størmer number.

The Bishnois community follows 29 principles. Guru Jambheshwar had laid down 29 principles to be followed by the sect in 1485 A.D. In Hindi, Bish means 20 and noi means 9; thus, Bishnoi translates as Twenty-niners.

The Saros number^{[dead link]} of the solar eclipse series which began on -1881 March 1 and ended on -583 April 19. The duration of Saros series 29 was 1298.1 years, and it contained 73 solar eclipses.

The Saros number of the lunar eclipse series which began on -1814 July 21 and ended on -317 January 5. The duration of Saros series 29 was 1496.5 years, and it contained 84 lunar eclipses.

Twenty-nine is:

The number of days February has in leap years.
The number of letters in the Turkish,^[1] Finnish, Swedish,^[2] Faroese,^[3] and Norwegian^[4] alphabets.
The designation of Interstate 29, a U. S. freeway that runs from Missouri to North Dakota.
In the name of the town Twentynine Palms, California, also the name of the adjoining Marine Corps Air Ground Combat Center Twentynine Palms, affectionately referred to by Marines as "Twentynine Stumps".^[5]
The number of suras in the Qur'an that begin with muqatta'at
The highest possible score in a hand of Cribbage.
The highest possible score in a hand of Khanhoo.
An album by Ryan Adams.^[6]
The track the Chattanooga Choo Choo leaves in the Glenn Miller song.
29th Regiment of Foot, a former regiment in the British Army.
The retired jersey number of Rod Carew
The Olympiad number of the 2008 Summer Olympics
The number of the French department Finistère
The amount of attributes existing according to The Strokes in You Only Live Once.
The retired S.L. Benfica shirt number in memory of Miklos Feher.
The number every woman in the "wrong age" claims to be. According to "The Nanny".
The number of CMS Baseball Star John "Zach" "Jay-Z" England
The number of Knuts in one Sickle in the fictional currency in the Harry Potter novels

29 B.C., 29 A.D., 1929, 2029, etc.

^ Caroline Finkel, Osman's Dream. New York: Basic Books (2006): xv. "The modern Turkish alphabet has 29 letters, of which three vowels and three consonants are unfamiliar to those who do not know the language, and one consonant is pronounced differently from English."
^ [1]
^ [2]
^ Anthony Ham, Miles Roddis & Graeme Cornwallis, Norway. New York: Lonely Planet (2005): 413. "The modern Norwegian alphabet has 29 letters: those used in English, plus the vowels æ, ø and a (which are listed at the end of the alphabet)."
^ Stephen F. Tomajczyk, To Be a U.S. Marine. New York: Zenith Imprint (2004): 155. "Twenty-nine stumps—Slang for Twenty-nine Palms Marine Corps Air-Ground Combat Center, located in California's Mojave Desert."
^ Hasty, Katie (2007-06-03). "Busy and bored, Adams tames "Tiger"". Reuters/ Billboard. Retrieved 2007-06-04. The first of the trio, "Cold Roses," has sold 159,000 copies in the United States, according to Nielsen SoundScan. "Jacksonville City Nights" has moved 100,000, and "29" has shifted 81,000.^{[dead link]}