43 (number)
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43 is the natural number following 42 and preceding 44.
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| Cardinal | forty-three | ||
| Ordinal | 43rd (forty-third) | ||
| Factorization | prime | ||
| Roman numeral | XLIII | ||
| Binary | 101011 | ||
| Hexadecimal | 2B | ||
In mathematics
Forty-three is the 14th smallest prime number. The previous is forty-one, with which it comprises a twin prime, the next is forty-seven. 43 is a centered heptagonal number.
Let a(0) = a(1) = 1, and thenceforth a(n) = (a(0)2 + a(1)2 + ... + a(n-1)2) / (n-1). This sequence continues 1 1 2 3 5 10 28 154... Template:OEIS. Amazingly, a(43) is the first term of this sequence that is not an integer.
Negative forty-three (-43) is a Heegner number.
In science
- The atomic number of technetium
In astronomy,
- Messier object M43, a magnitude 7.0 H II region in the constellation of Orion, a part of the Orion Nebula, and also sometimes known as de Mairan's Nebula
- The New General Catalogue object (http://www.ngcic.org/) NGC 43, a barred spiral galaxy in the constellation Andromeda
- The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on -1512 April 29 and ended on -232 June 5. The duration of Saros series 43 was 1280.1 years, and it contained 72 solar eclipses.
- The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -1481 August 27 and ended on 70 March 15. The duration of Saros series 43 was 1550.5 years, and it contained 87 lunar eclipses.
In other fields
Forty-three is also:
- The designation of Interstate 43, a freeway in Wisconsin.
- The code for direct dial international phone calls to Austria.
- Part of the title of the historical British comedy show Hancock's Forty-Three Minutes, starring Tony Hancock.
- Part of the title of a historical short story by Hershel Finman titled Forty-Three Rubles, about Rabbi Zvi Elimelech Spira.
- The year AD 43, 43 BC, and 1943.es:Cuarenta y tres
eo:Kvardek tri fr:Quarante-trois ko:43 ia:43 it:Quarantatr nl:43 (getal) ja:43 pt:Quarenta e trs ru:43 (число) sl:43 (število) sv:43 (tal) zh:43