29 (number)

← 28 30 → 29
← 20 21 22 23 24 25 26 27 28 29 → List of numbers — Integers 0 10 20 30 40 50 60 70 80 90 →
Cardinal	twenty-nine
Ordinal	29th (twenty-ninth)
Factorization	prime
Divisors	1, 29
Roman numeral	XXIX
Binary	111012
Octal	358
Duodecimal	2512
Hexadecimal	1D16

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.

29 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 x² + y² + z² = 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.

In science

• The atomic number of copper

• A lunar month is approximately 29 days.

In religion

• 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.

In astronomy

• Messier object M29, a magnitude 9.0 open cluster in the constellation Cygnus

• The New General Catalogue object NGC 29, a spiral galaxy in the constellation Andromeda

• The lunar month is very close to twenty-nine days.

• Saturn requires over 29 years to orbit the Sun

In other fields

Twenty-nine is:

• The number of days February has in leap years.
• The number of letters in the Turkish, Finnish, Swedish, Faroese, Danish and Norwegian 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".
• The number of suras in the Qur'an that begin with muqatta'at
• The highest possible score in a hand of Cribbage or Khanhoo.
• An album by Ryan Adams.
• 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 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
• "$29.00" is a song on the album Blue Valentine by Tom Waits.

Historical years

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

References

• Prime Curios! 29 from the Prime Pages

External links

• On the number 29 at Wisdom Portal