67 (number) - Definition and Overview

67 is the natural number following 66 and preceding 68.

In mathematics

Sixty-seven is the 19th prime number (the next is 71), an irregular prime, a lucky prime, and the sum of five consecutive primes (7 + 11 + 13 + 17 + 19). It is a discriminant to the Heegner number -67.

In science

• The atomic number of holmium, a lanthanide

In astronomy,

Messier object M67, a magnitude 7.5 open cluster in the constellation Cancer

The New General Catalogue object (http://www.ngcic.org/) NGC 67, an elliptical 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 -727 February 20 and ended on 571 April 10. The duration of Saros series 67 was 1298.1 years, and it contained 73 solar eclipses.

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on -660 July 1 and ended on 656 September 9. The duration of Saros series 67 was 1316.2 years, and it contained 74 lunar eclipses.

Other fields

Sixty-seven is also:

• The registry of the U.S. Navy's aircraft carrier USS John F. Kennedy (CV-67), named after U.S. President John F. Kennedy.
• The number of the French department Bas-Rhin.
• Part of the name of the Ottawa 67's, founded in 1967.
• The year AD 67, 67 BC, or 1967.