5040 (number)

Last updated
503950405041
Cardinal five thousand forty
Ordinal 5040th
(five thousand fortieth)
Factorization 24 × 32 × 5 × 7
Divisors 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 24, 28, 30, 35, 36, 40, 42, 45, 48, 56, 60, 63, 70, 72, 80, 84, 90, 105, 112, 120, 126, 140, 144, 168, 180, 210, 240, 252, 280, 315, 336, 360, 420, 504, 560, 630, 720, 840, 1008, 1260, 1680, 2520, 5040
Greek numeral ,ΕΜ´
Roman numeral VXL
Binary 10011101100002
Ternary 202202003
Senary 352006
Octal 116608
Duodecimal 2B0012
Hexadecimal 13B016

5040 (five thousand [and] forty) is the natural number following 5039 and preceding 5041.

Contents

It is a factorial (7!), a superior highly composite number, abundant number, colossally abundant number and the number of permutations of 4 items out of 10 choices (10 × 9 × 8 × 7 = 5040). It is also one less than a square, making (7, 71) a Brown number pair.

Philosophy

Plato mentions in his Laws that 5040 is a convenient number to use for dividing many things (including both the citizens and the land of a city-state or polis ) into lesser parts, making it an ideal number for the number of citizens (heads of families) making up a polis. [1] He remarks that this number can be divided by all the (natural) numbers from 1 to 12 with the single exception of 11 (however, it is not the smallest number to have this property; 2520 is). He rectifies this "defect" by suggesting that two families could be subtracted from the citizen body to produce the number 5038, which is divisible by 11. Plato also took notice of the fact that 5040 can be divided by 12 twice over. Indeed, Plato's repeated insistence on the use of 5040 for various state purposes is so evident that Benjamin Jowett, in the introduction to his translation of Laws, wrote, "Plato, writing under Pythagorean influences, seems really to have supposed that the well-being of the city depended almost as much on the number 5040 as on justice and moderation." [2]

Jean-Pierre Kahane has suggested that Plato's use of the number 5040 marks the first appearance of the concept of a highly composite number, a number with more divisors than any smaller number. [3]

Number theoretical

If is the sum-of-divisors function and is the Euler–Mascheroni constant, then 5040 is the largest of 27 known numbers (sequence A067698 in the OEIS ) for which this inequality holds:

.

This is somewhat unusual, since in the limit we have:

Guy Robin showed in 1984 that the inequality fails for all larger numbers if and only if the Riemann hypothesis is true.

Interesting notes

Related Research Articles

In number theory, an arithmetic, arithmetical, or number-theoretic function is generally any function f(n) whose domain is the positive integers and whose range is a subset of the complex numbers. Hardy & Wright include in their definition the requirement that an arithmetical function "expresses some arithmetical property of n". There is a larger class of number-theoretic functions that do not fit this definition, for example, the prime-counting functions. This article provides links to functions of both classes.

In mathematics, the factorial of a non-negative integer , denoted by , is the product of all positive integers less than or equal to . The factorial of also equals the product of with the next smaller factorial: For example, The value of 0! is 1, according to the convention for an empty product.

<span class="mw-page-title-main">Divisor</span> Integer that is a factor of another integer

In mathematics, a divisor of an integer also called a factor of is an integer that may be multiplied by some integer to produce In this case, one also says that is a multiple of An integer is divisible or evenly divisible by another integer if is a divisor of ; this implies dividing by leaves no remainder.

<span class="mw-page-title-main">Euler's totient function</span> Number of integers coprime to and not exceeding n

In number theory, Euler's totient function counts the positive integers up to a given integer n that are relatively prime to n. It is written using the Greek letter phi as or , and may also be called Euler's phi function. In other words, it is the number of integers k in the range 1 ≤ kn for which the greatest common divisor gcd(n, k) is equal to 1. The integers k of this form are sometimes referred to as totatives of n.

A highly composite number is a positive integer that has more divisors than any smaller positive integer. A related concept is that of a largely composite number, a positive integer that has at least as many divisors as any smaller positive integer. The name can be somewhat misleading, as the first two highly composite numbers are not actually composite numbers; however, all further terms are.

<span class="mw-page-title-main">Table of divisors</span>

The tables below list all of the divisors of the numbers 1 to 1000.

<span class="mw-page-title-main">Multiply perfect number</span> Number whose divisors add to a multiple of that number

In mathematics, a multiply perfect number is a generalization of a perfect number.

27 is the natural number following 26 and preceding 28.

<span class="mw-page-title-main">Divisor function</span> Arithmetic function related to the divisors of an integer

In mathematics, and specifically in number theory, a divisor function is an arithmetic function related to the divisors of an integer. When referred to as the divisor function, it counts the number of divisors of an integer. It appears in a number of remarkable identities, including relationships on the Riemann zeta function and the Eisenstein series of modular forms. Divisor functions were studied by Ramanujan, who gave a number of important congruences and identities; these are treated separately in the article Ramanujan's sum.

<span class="mw-page-title-main">360 (number)</span> Natural number

360 is the natural number following 359 and preceding 361.

One half is the irreducible fraction resulting from dividing one (1) by two (2), or the fraction resulting from dividing any number by its double.

2520 is the natural number following 2519 and preceding 2521.

In mathematics, an untouchable number is a positive integer that cannot be expressed as the sum of all the proper divisors of any positive integer. That is, these numbers are not in the image of the aliquot sum function. Their study goes back at least to Abu Mansur al-Baghdadi, who observed that both 2 and 5 are untouchable.

<span class="mw-page-title-main">Practical number</span> Number such that it and all smaller numbers may be represented as sums of its distinct divisors

In number theory, a practical number or panarithmic number is a positive integer such that all smaller positive integers can be represented as sums of distinct divisors of . For example, 12 is a practical number because all the numbers from 1 to 11 can be expressed as sums of its divisors 1, 2, 3, 4, and 6: as well as these divisors themselves, we have 5 = 3 + 2, 7 = 6 + 1, 8 = 6 + 2, 9 = 6 + 3, 10 = 6 + 3 + 1, and 11 = 6 + 3 + 2.

In mathematics, a superabundant number is a certain kind of natural number. A natural number n is called superabundant precisely when, for all m < n:

<span class="mw-page-title-main">Colossally abundant number</span> Type of natural number

In number theory, a colossally abundant number is a natural number that, in a particular, rigorous sense, has many divisors. Particularly, it is defined by a ratio between the sum of an integer's divisors and that integer raised to a power higher than one. For any such exponent, whichever integer has the highest ratio is a colossally abundant number. It is a stronger restriction than that of a superabundant number, but not strictly stronger than that of an abundant number.

<span class="mw-page-title-main">Highly abundant number</span> Natural number whose divisor sum is greater than that of any smaller number

In number theory, a highly abundant number is a natural number with the property that the sum of its divisors is greater than the sum of the divisors of any smaller natural number.

225 is the natural number following 224 and preceding 226.

In mathematics, specifically in number theory, the extremal orders of an arithmetic function are best possible bounds of the given arithmetic function. Specifically, if f(n) is an arithmetic function and m(n) is a non-decreasing function that is ultimately positive and

<span class="mw-page-title-main">Perrin number</span> Number sequence 3,0,2,3,2,5,5,7,10,...

In mathematics, the Perrin numbers are a doubly infinite constant-recursive integer sequence with characteristic equation x3 = x + 1. The Perrin numbers bear the same relationship to the Padovan sequence as the Lucas numbers do to the Fibonacci sequence.

References

  1. Pangle, Thomas L. (1988). The Laws of Plato. Chicago University Press. pp. 124–5. ISBN   9780226671109.
  2. Laws, by Plato, translated By Benjamin Jowett, at Project Gutenberg; retrieved 7 July 2009.
  3. Kahane, Jean-Pierre (February 2015), "Bernoulli convolutions and self-similar measures after Erdős: A personal hors d'oeuvre" (PDF), Notices of the American Mathematical Society, 62 (2): 136–140.