Twenty-nine (29, XXIX) is the natural number following twenty-eight and preceding thirty. It is the tenth prime number, and also a primorial prime, the next prime number as well as primoral prime being thirty-one, with which it comprises a twin prime. Twenty-nine is also the sum of three squares, 22 + 32 + 42. It is a Lucas number and a Pell number.
The lunar month is very close to twenty-nine days.
Twenty-nine is also
- The atomic number of copper.
- The number of days February has on leap years.
- The number of letters in the Finnish and Norwegian alphabets.
- The designation of Interstate 29, a 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 base, affectionately referred to by Marines as "Twentynine Stumps".
See also: twenty-seven, twenty-eight, thirty, thirty-one, integer, list of numbers.
This article is about the number. For the year AD 29, see 29.