47 (number)

Short description: Natural number

← 46 47 48 →
← 40 41 42 43 44 45 46 47 48 49 → List of numbers — Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	forty-seven
Ordinal	47th (forty-seventh)
Factorization	prime
Prime	15th
Divisors	1, 47
Greek numeral	ΜΖ´
Roman numeral	XLVII
Binary	1011112
Ternary	12023
Quaternary	2334
Quinary	1425
Senary	1156
Octal	578
Duodecimal	3B12
Hexadecimal	2F16
Vigesimal	2720
Base 36	1B36

47 (forty-seven) is the natural number following 46 and preceding 48. It is a prime number.

In mathematics

Forty-seven is the fifteenth prime number, a safe prime, the thirteenth supersingular prime, the fourth isolated prime, and the sixth Lucas prime. Forty-seven is a highly cototient number. It is an Eisenstein prime with no imaginary part and real part of the form 3n − 1.

It is a Lucas number. It is also a Keith number because its digits appear as successive terms earlier in the series of Lucas numbers: 2, 1, 3, 4, 7, 11, 18, 29, 47, ...

It is the number of trees on 9 unlabeled nodes.

Forty-seven is a strictly non-palindromic number.

Its representation in binary being 101111, 47 is a prime Thabit number, and as such is related to the pair of amicable numbers {17296, 18416}.

In science

• 47 is the atomic number of silver.

Astronomy

• The 47-year cycle of Mars: after 47 years – 22 synodic periods of 780 days each – Mars returns to the same position among the stars and is in the same relationship to the Earth and Sun. The ancient Mesopotamians discovered this cycle.
• Messier object M47, a magnitude 4.5 open cluster in the constellation Puppis
• 47 Tucanae, the second brightest globular cluster in the sky, located in the constellation Tucana.
• The New General Catalogue object NGC 47, a barred spiral galaxy in the constellation Cetus. This object is also designated as NGC 58.

In popular culture

Pomona College

The Smith Clock Tower (right) at Pomona College has been set up to chime on the 47th minute of the hour.

This section is an excerpt from Traditions of Pomona College § 47 reverence[ edit ]

Other

Agent 47 is the protagonist of the Hitman video game, movie and comic book franchise.

Late rapper Capital Steez was infatuated with the number 47 and what it meant spiritually. He believed the number 47 was the "perfect expression of balance in the world", representing the tension between the heart and the brain (the fourth and seventh chakra, respectively.) The number featured on the cover of AmeriKKKan Korruption, stylized to resemble a swastika.

Calendar years

• 47 BC
• AD 47

See also

• List of highways numbered 47

Other

• Telephone dialing country code for Norway
• The AK-47, also known as a Kalashnikov rifle, is one of the most widely used military weapons in the world.
• The CH-47 Chinook, a helicopter.
• 47 is the number of the French department Lot-et-Garonne.
• The P-47 Thunderbolt was a fighter plane in World War II.
• There are Forty-seven Ronin in the famous Japanese story.
• There are 47 Prefectures of Japan.
• The player protagonist of the Hitman video game franchise is called Agent 47.