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 astronomy

• Messier object M67, a magnitude 7.5 open cluster in the constellation Cancer
• The New General Catalogue object NGC 67 , an elliptical galaxy in the constellation Andromeda
• The Saros number 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 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 atomic number of holmium, a lanthanide
• 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 European route E67, the Via Baltica from Prague to Helsinki.
• 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.