|Roman numeral||V, v|
|Greek||ε (or Ε)|
|Persian, Sindhi, Urdu||۵|
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. It has attained significance throughout history in part because typical humans have five digits on each hand.
Five is the third smallest prime number. Since it can be written as 22 + 1, five is classified as a Fermat prime; therefore, a regular polygon with 5 sides (a regular pentagon) is constructible with compass and an unmarked straightedge. Five is the third Sophie Germain prime, the first safe prime, the third Catalan number, and the third Mersenne prime exponent. Five is the first Wilson prime and the third factorial prime, also an alternating factorial. Five is the first good prime. It is an Eisenstein prime with no imaginary part and real part of the form 3p − 1. It is also the only number that is part of more than one pair of twin primes. Five is also a super-prime, and a congruent number.
Five is conjectured to be the only odd untouchable number, and if this is the case then five will be the only odd prime number that is not the base of an aliquot tree.
Five is also the only prime that is the sum of two consecutive primes, namely 2 and 3, with these indeed being the only possible set of two consecutive primes.
The number 5 is the fifth Fibonacci number, being 2 plus 3. It is the only Fibonacci number that is equal to its position. Five is also a Pell number and a Markov number, appearing in solutions to the Markov Diophantine equation: (1, 2, 5), (1, 5, 13), (2, 5, 29), (5, 13, 194), (5, 29, 433), ... (OEIS: A030452 lists Markov numbers that appear in solutions where one of the other two terms is 5). Whereas 5 is unique in the Fibonacci sequence, in the Perrin sequence 5 is both the fifth and sixth Perrin numbers.
5 is the length of the hypotenuse of the smallest integer-sided right triangle.
In bases 10 and 20, 5 is a 1-automorphic number.
Five is the second Sierpinski number of the first kind, and can be written as S2 = (22) + 1.
While polynomial equations of degree 4 and below can be solved with radicals, equations of degree 5 and higher cannot generally be so solved. This is the Abel–Ruffini theorem. This is related to the fact that the symmetric group Sn is a solvable group for n ≤ 4 and not solvable for n ≥ 5.
While all graphs with 4 or fewer vertices are planar, there exists a graph with 5 vertices which is not planar: K5, the complete graph with 5 vertices.
There are five Platonic solids.
A polygon with five sides is a pentagon. Figurate numbers representing pentagons (including five) are called pentagonal numbers. Five is also a square pyramidal number.
Five is the only prime number to end in the digit 5 because all other numbers written with a 5 in the ones place under the decimal system are multiples of five. As a consequence of this, 5 is in base 10 a 1-automorphic number.
Vulgar fractions with 5 or 2 in the denominator do not yield infinite decimal expansions, unlike expansions with all other prime denominators, because they are prime factors of ten, the base. When written in the decimal system, all multiples of 5 will end in either 5 or 0.
There are five exceptional Lie groups.
|5 × x||5||10||15||20||25||30||35||40||45||50||55||60||65||70||75||80||85||90||95||100|
|5 ÷ x||5||2.5||1.6||1.25||1||0.83||0.714285||0.625||0.5||0.5||0.45||0.416||0.384615||0.3571428||0.3|
|x ÷ 5||0.2||0.4||0.6||0.8||1||1.2||1.4||1.6||1.8||2||2.2||2.4||2.6||2.8||3|
In the powers of 5, every power ends with the number five and from 53, if the exponent is odd, then the hundreds digit is 1; instead, if it is even, the hundreds digit is 6.
In decimal notation, n5 always ends in the same digit as n.
The evolution of the modern Western digit for the numeral 5 cannot be traced back to the Indian system, as for the digits 1 to 4. The Kushana and Gupta empires in what is now India had among themselves several different forms that bear no resemblance to the modern digit. The Nagari and Punjabi took these digits and all came up with forms that were similar to a lowercase "h" rotated 180°. The Ghubar Arabs transformed the digit in several different ways, producing from that were more similar to the digits 4 or 3 than to 5. It was from those digits that Europeans finally came up with the modern 5.
While the shape of the character for the digit 5 has an ascender in most modern typefaces, in typefaces with text figures the glyph usually has a descender, as, for example, in.
Five can refer to:
The five appendages of the starfish are thought to be homologous to five human buds
where Category 5 includes the most powerful hurricane
The strongest tornado would be an F5
M5, like the previous objects in the Messier Catalogue is a globular star cluster in Serpen
The typical limb of tetrapods is the pentadactyl limb (Gr. penta, five) that has five toes. Tetrapods evolved from an ancestor that had limbs with five toes. ... Even though the number of digits in different vertebrates may vary from five, vertebrates develop from an embryonic five-digit stage.
5 5 005 ENQ (enquiry)
Shiva has five faces;
The Psalms are arranged into five books
...he prescribed five sacred symbols to create a unified ident
using the title the Five Emperors
The first category is the Five Agents [Elements] namely, Water, Fire, Wood, Metal, and Earth.
The Japanese names of the days of the week are taken from the names of the seven basic nature symbols
Nation of Gods and Earths (also known as the Five Percenters),
Meet Sodor's number 5 engine
the super-robot Number 5 in the film Short Circuit,
he gave him the five sacred stones with magical properties
These five included the head wizard,
...view the events of A Song of Ice and Fire. As we'll see, the War of the Five Kings
Also sometimes referred to as 'The Mighty Five' or 'Mighty Handful': Balakirev, Rimsky Korsakov, Borodin, Cui and Musorgsky
are the perfect fourth, perfect fifth, and the octave
the five lines and four spaces between them on which musical notes are written
Quintet 1 An ensemble made up of five instruments or voices
Pentatonic scales, as used in jazz, are five note scales
Major penalties of five minutes
scoring five goals in five different ways: an even-strength goal, a power-play goal, a shorthanded goal, a penalty shot goal...
five-hole the space between a goaltender's legs
a “try,” worth 5 points;
The 5 - speed manual gearbox is likely to remain the most common type
the number 5 key has a raised bar or dot that helps you identify it by touch
...digit in the phone number is a 5 , which corresponds to the triplet J , K , L
The Pentium is a fifth-generation x86 architecture...
...another picture of one of the world's most famous babies was made. Fred Davis is official photographer of the Dionne quintuplets...
Someone who stands on his or her right to avoid self incrimination is said in street language to be “taking the Fifth,” or “pleading the Fifth.”
The most common accentual-syllabic lines are five-foot iambic lines (iambic pentameter)
Plato and Aristotle postulated a fifth state of matter, which they called "idea" or quintessence" (from "quint" which means "fifth")
North - south highways got odd numbers , the most important ending in 5
There are five basic tastes: sweet, salty, sour, bitter and umami...
Law of Fives is never wrong'. This law is the reason 23 is a significant number for Discordians...
...Justice Brennan's infamous "Rule of Five,"
quincunx five points
The five permanent members have a veto power over actions proposed by members of the United Nations.
...between two of a pentagon's five interior angles to the length of any of its five sides is the golden section..
...the pentacle as a five-pointed star (pentagram) ...
There are five Korotkoff phases...
...said to derive from Hindi panch "five," in reference to the number of original ingredients
On Friday, June 28, the Committee of Five delivered its revised draft of Jefferson's draft of the Declaration of Independence
His newest characters: a boy named 555 95472, or 5 for short,