77 (number)

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

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.

List of numbers — Integers << 70 71 72 73 74 75 76 77 78 79 >>
Cardinal	seventy-seven
Ordinal	77th (seventy-seventh)
Factorization	:<math>7 \cdot 11<math>
Roman numeral	LXXVII
Binary	1001101
Hexadecimal	4D

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

Seventy-seven is also:

• The atomic number of iridium.
• The designation of Interstate 77, a freeway that runs from South Carolina to Ohio.
• The registry of the U.S. Navy's in-construction nuclear aircraft carrier USS George H. W. Bush (CVN-77), named after U.S. President George H. W. Bush.
• The year AD 77, 77 BC, or 1977.
• The flight number of the aircraft that crashed into the Pentagon on September 11, 2001
• Part of the name of a 50's and 60's era televsion program: 77 Sunset Strip.