77 (number)

← 76 77 78 →
← 70 71 72 73 74 75 76 77 78 79 → List of numbers — Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	seventy-seven
Ordinal	77th (seventy-seventh)
Factorization	7 · 11
Divisors	1, 7, 11, 77
Roman numeral	LXXVII
Binary	10011012
Ternary	22123
Quaternary	10314
Octal	1158
Duodecimal	6512
Hexadecimal	4D16
Vigesimal	3H20
Base 36	2536

77 (seventy-seven) is the natural number following 76 and preceding 78. Seventy-seven is the smallest positive integer requiring five syllables in English.

In mathematics

Seventy-seven is the 22nd discrete biprime and the first of the (7.q) family. Since both 7 and 11 are Gaussian primes, this means that 77 is a Blum integer.

77 has an aliquot sum of 19 and it is the second number to do so the first being 65; 77 is the 2nd member of the 19-aliquot tree.

It is the sum of three squares, 4² + 5² + 6², as well as the sum of the first eight prime numbers.

It also is the number of integer partitions of the number 12.

It is the largest number that cannot be written as a sum of distinct numbers whose reciprocals sum to 1.

77 and 78 form a Ruth–Aaron pair.

It is possible for a sudoku puzzle to have as many as 77 givens, yet lack a unique solution.

It and its sibling 49 are the only 2-digit numbers whose home primes (in base 10) have not been calculated.

It is the number of digits of the 12th perfect number.

In science

• The atomic number of iridium

In numerology

In certain numerological systems based on the English alphabet, the number 77 is associated with Jesus Christ. CHRIST is C = 3, H = 8, R = 18, I = 9, S = 19, T = 20, which added together equal 77. The letters of JESUS equal 74 when added together: J = 10, E = 5, S = 19, U = 21, S = 19. Thus, JESUS CHRIST can be represented as 151 in numerology based on the English alphabet.^{[citation needed]}

In history

During World War II in Sweden at the border with Norway, "77" was used as a shibboleth (password), because the tricky pronunciation in Swedish made it easy to instantly discern whether the speaker was native Swedish, Norwegian, or German.^{[citation needed]}

In religion

In the Islamic tradition, "77" figures prominently. Muhammad is reported to have explained, "Faith has sixty-odd, or seventy-odd branches, the highest and best of which is to declare that there is no god but God, and the lowest of which is to remove something harmful from a road. Shyness, too, is a branch of faith." While some scholars refrain from clarifying "sixty-odd or seventy-odd", various numbers have been suggested, 77 being the most common. Some have gone so far as to delineate these branches.

In sports

• Portland Trail Blazers coach Jack Ramsay led his team to their only NBA title in his first season. #77 was retired in honor of the 1977 NBA title.
• The number posthumously retired by the Minnesota Vikings of the NFL for offensive lineman Korey Stringer.
• The number worn by Ray Bourque in the NHL from 1987 to 2001. This number has been retired by the Boston Bruins, with whom he played for 20 years, and the Colorado Avalanche, with whom he won the Stanley Cup in his last NHL game. He wore 77 after his previous number (7), which he wore for his first eight seasons, was retired for Phil Esposito.
• The number worn by football legend Red Grange. Retired by both the University of Illinois and the Chicago Bears.
• The number worn by NFL Hall of Famer Jim Parker. Retired by the Indianapolis Colts
• The number worn by NFL offensive tackle Stan Mauldin. Retired by the Arizona Cardinals.
• The number worn by NCAA football legend Dennis Byrd. Retired by NC State in 2001.
• The number worn by NCAA football legend John Schmitt. Retired by Hofstra University.
• The number worn by Alex Melvin of the Pickering Red Sox (PBA). Retired in 2009.
• The number worn by NCAA basketball legend Bill Spivey. Retired by the University of Kentucky.

In other fields

Seventy-seven is also:

• 10-77 – the fire departments' 10 code for high-rise, multiple-dwelling fire^{[citation needed]}
• Group of 77, a group of developing nations at the United Nations
• 77 – 1977 Talking Heads album (Talking Heads: 77) released in 1977
• The 77's, an American Rock band