61 (number)

61 (sixty-one) is the natural number following 60 and preceding 62.

In mathematics

61 is:

*the 18th prime number.
*a twin prime with 59.
*a cuban prime of the form ''p'' = , where ''x'' = ''y'' + 1.
*the smallest ''proper prime'', a prime ''p'' which ends in the digit 1 in base 10 and whose reciprocal in base 10 has a repeating sequence with length ''p'' − 1. In such primes, each digit 0, 1, ..., 9 appears in the repeating sequence the same number of times as does each other digit (namely, times).
*the exponent of the 9th Mersenne prime. (2⁶¹ − 1 = )
*the sum of two squares, 5² + 6².
*a centered square number.
*a centered hexagonal number.
*a centered decagonal number.
*the sixth Euler zigzag number (or Up/down number).
*a unique prime in base 14, since no other prime has a 6-digit period in base 14.
*a Pillai prime since 8! + 1 is divisible by 61 but 61 is not one more than a multiple of 8.
*a Keith number, because it recurs in a Fibonacci-like sequence started from its base 10 digits: 6, 1, 7, 8, 15, 23, 38, 61...
*palindromic in bases 6 (141₆) and 60 (11₆₀)

In the list of Fortunate numbers, 61 occurs thrice, since adding 61 to either the tenth, twelfth or seventeenth primorial gives a prime number (namely 6,469,693,291; 7,420,738,134,871; and 1,922,760,350,154,212,639,131).

In science

* The chemical element with the atomic number 61 is promethium.

Astronomy

*Messier object M61, a magnitude 10.5 galaxy in the constellation Virgo
*The New General Cataloguebr>object
NGC 61, a double spiral galaxy in the constellation Cetus
*61 Ursae Majoris is located about 31.1 light-years from the Sun

*61 Cygni was christened the "Flying Star" in 1792 by Giuseppe Piazzi (1746–1826) for its unusually large proper motion

In other fields

Sixty-one is:
* The number of the French department Orne phone calls to Australia
* '' 61*'', a 2001 baseball movie directed by Billy Crystal
* ''Highway 61 Revisited'' is a Bob Dylan album
* The Highway 61 Blues Festival occurs annually in Leland, Mississippi
* '' Highway 61'' is a 1991 film set on U.S. Route 61
* U.S. Route 61 is the highway that inspired so much attention on "Highway 61"
* Part 61 is a law created by the FAA regarding medical exams. This law has often come under attack by AOPA.
* The P-61 is the Northrop-designed fighter first designated as the XP-61. It first flew on May 26, 1942. It is also known as the ''Black Widow'' as it was the first fighter aircraft designed to be a night fighter
* Sixty 1 is a brand tobacco produced by Nationwide Tobacco
* 61A is the London address of Margot Wendice (Grace Kelly) and Tony Wendice ( Ray Milland) in the movie ''Dial M for Murder''
* 1 Liberty Place is Philadelphia's tallest building at 61 stories
* The number of cadets on The Summerall Guards
* The number of points required to win a "standard" game of cribbage
* The maximum number of tables that can be joined in a single MariaDB or MySQL queryMySQL Reference Manual – JOIN clause
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In sports

* New York Yankees right fielder Roger Maris hit 61 home runs in 1961, breaking Babe Ruth's single-season record until it was surpassed in 1998 by Mark McGwire and Sammy Sosa.
* Nolan Ryan and Tom Seaver each had 61 career shutouts
* Hockey great Wayne Gretzky holds or shares 61 NHL records (40 for regular season, 15 for Stanley Cup playoff, and 6 for All-Star Games)
* Rotation, a variation of pool, is sometimes called 61
* Richie Evans' NASCAR Whelen Modified Tour car number was 61 until his death in 1985
*The number of the laps of the first Formula One night race, Singapore Grand Prix.

References

* R. Crandall and C. Pomerance (2005). ''Prime Numbers: A Computational Perspective''. Springer, NY, 2005, p. 79.

External links

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Integers