65 (number)

← 64 65 66 →
←60616263646566676869→ List of numbers Integers ←0102030405060708090→
Cardinal	sixty-five
Ordinal	65th (sixty-fifth)
Factorization	5 × 13
Divisors	1, 5, 13, 65
Greek numeral	ΞΕ´
Roman numeral	LXV
Binary	10000012
Ternary	21023
Senary	1456
Octal	1018
Duodecimal	5512
Hexadecimal	4116

65(sixty-five) is thenatural numberfollowing64and preceding66.

In mathematics

65 as the sum of distinct positive squares.

65 is the nineteenth distinctsemiprime,(5.13); and the third of the form (5.q), where q is a higher prime.

65 has a primealiquot sumof19within analiquot sequenceof one composite numbers (65,19,1,0) to the prime; as the first member' of the19-aliquot tree.

It is anoctagonal number.It is also aCullen number.Given 65, theMertens functionreturns0.

This number is themagic constantof a 5x5 normalmagic square:

${\begin{bmatrix}17&24&1&8&15\\23&5&7&14&16\\4&6&13&20&22\\10&12&19&21&3\\11&18&25&2&9\end{bmatrix}}.$

This number is also the magic constant ofn-Queens Problemfor n = 5.

65 is the smallestintegerthat can be expressed as a sum of two distinct positive squares in two (or more) ways, 65 = 8²+ 1²= 7²+ 4².

It appears in thePadovan sequence,preceded by the terms 28, 37, 49 (it is the sum of the first two of these).

65 is aStirling number of the second kind,the number of ways of dividing a set of six objects into four non-empty subsets.

65 = 1⁵+ 2⁴+ 3³+ 4²+ 5¹.

65 is the length of the hypotenuse of 4 differentPythagorean triangles,the lowest number to have more than 2: 65²= 16²+ 63²= 33²+ 56²= 39²+ 52²= 25²+ 60².The first two are "primitive", and 65 is the lowest number to be the largest side of more than one such triple.

65 is the number of compositions of 11 into distinct parts.

In science

• Theatomic numberofterbium,a lanthanide

Astronomy

• Messier objectM65,agalaxyofmagnitude10.5 in theconstellationLeo
• TheNew General CatalogueobjectNGC 65,aspiral galaxyin the constellationCetus

In music

• "65 Love Affair",singer Paul Davis' hit song in 1982
• Sammy Hagarre-recorded his hit "I Can't Drive 55", with the 55 changed to 65, in 2001 for NBC's NASCAR broadcasts to reflect higher speed limits; the song was used from 2001 until 2004 to introduce Budweiser Pole Award winners on NBC and TNT broadcasts
• 65 is a commonly used abbreviation for the Sheffield, UK, post-rock band65daysofstatic
• Referenced in "Heroes and Villains"by the Beach Boys:" At 60 and 5 / I'm very much alive / I've still got the jive / to survive with the Heroes and Villains "
• Odd FuturegroupMellowHypehas performed a song entitled "65"

In other fields

See also:List of highways numbered 65

• 65 miles per hour is a commonspeed limitonexpresswaysin manyU.S. states,primarily in the eastern and central United States. (In the western United States, a common speed limit is 70 m.p.h., and in some places it is 75 m.p.h.).
• +65is thecode for international direct dialtelephone calls to Singapore.
• the traditional age for retirement in the United Kingdom, Germany, the United States, Canada, and several other countries.
  • in the U.S., the age at which a person is eligible to obtain Medicare.
• CVN-65 is the designation of the U.S. Navy's first nuclear-poweredaircraft carrier,theUSSEnterprise(CVN-65).
• 65 is the minimum grade or average required to pass an exam, or a class, in some schools.
• The setting of the American classicTV seriesNaked City(1958–1963) was the 65th Precinct inNew York City(sometimes referred to as simply "the 65" ).
• 65 is the number of the French departmentHautes-Pyrénées.
• 65 is commonly used in names of many dishes ofSouth Indiacuisine, for instanceChicken 65.
• TheM-65 field jacketwas commonly worn by American troops during theWar in Vietnam.
• A 65th anniversary is sometimes referred to as asapphire jubilee.
• TheAGM-65 Maverickis a mass-produced air-to-ground tactical missile (AGM) designed for close air support against a wide range of targets.