29 (number)

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

List of numbers — Integers << 20 21 22 23 24 25 26 27 28 29 >>
Cardinal	twenty-nine
Ordinal	twenty-ninth
Factorization	prime
Roman numeral	XXIX
Binary	11101
Hexadecimal	1D

In mathematics

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 a Sophie Germain prime. It is also the sum of three squares, 2² + 3² + 4². It is a Lucas number, a Pell number and a tetranacci number.

In other fields

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

Twenty-nine is:

• 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".
• Historical years: 29 A.D., 29 B.C., or 1929