63

← 62 64 → 63
← 60 61 62 63 64 65 66 67 68 69 → List of numbers — Integers 0 10 20 30 40 50 60 70 80 90 →
Cardinal	sixty-three
Ordinal	63rd (sixty-third)
Factorization
Divisors	1, 3, 7, 9, 21, 63
Roman numeral	LXIII
Binary	1111112
Octal	778
Duodecimal	5312
Hexadecimal	3F16

63 (sixty-three) is a natural number following 62 and preceding 64.

In mathematics

Although a number of the form 2ⁿ - 1, 63 is not a Mersenne prime since n is not prime and 63 is certainly not prime either. It is a Woodall number and a Harshad number. It is a highly cototient number. It is a repdigit in base 4 (333). 63 is weak (63+36=99), but 64 is very strong.

In science

• The atomic number of europium, a lanthanide

Astronomy

• Messier object M63, a magnitude 8.5 galaxy in the constellation Canes Venatici, also known as the Sunflower Galaxy.

• The New General Catalogue object NGC 63, a spiral galaxy in the constellation Pisces

• The Saros number of the solar eclipse series which began on -879 April 20 and ended on 401 May 29. The duration of Saros series 63 was 1280.1 years, and it contained 72 solar eclipses.

• The Saros number of the lunar eclipse series which began on -758 October 12 and ended on 739 March 29. The duration of Saros series 63 was 1496.5 years, and it contained 84 lunar eclipses.

In other fields

Sixty-three is:

• Ascii for question mark: '?'
• The code for international direct dial calls to the Philippines
• The registry of the U.S. Navy's aircraft carrier USS Kitty Hawk (CV-63)
• The number of the French department Puy-de-Dôme
• The number of groats in a guinea in British pre-decimal currency
• A card game, popular in Carleton County, New Brunswick
• The Stoner 63, a machine gun
• The number of chromosomes found in the offspring of a donkey and a horse
• Class of '63 was a TV movie starring James Brolin (1973)
• December, 1963 (Oh, What a Night) sung by The Four Seasons
• Dwight Eisenhower when first elected president in 1952 at age 63
• Elizabeth Kingsley created the first double-crostic puzzle at age 63

In sports

• Tom Dempsey of New Orleans Saints, Nov. 8, 1970, and Jason Elam of the Denver Broncos, Oct. 25, 1988) had NFL record 63-yard field goals

• Indianapolis Colts Jeff Saturday wears #63

• NFL Houston Oilers Mike Munchak wore #63

• Kansas City Chiefs Willie Lanier wore #63

• Tampa Bay Buccaneers Lee Roy Selmon wore #63

• Michael Jordan scored a record 63 points in a Chicago Bulls –Boston Celtics (double-overtime) NBA playoff game on April 20, 1986

• Dallas Stars forward Mike Ribeiro wears #63

Historical years

63 B.C., 63 A.D., 1963, 2063, etc.