19 relations: Aliquot sum, Cambridge University Press, Deficient number, Divisor, Divisor function, Friendly number, Integer, Introduction to Arithmetic, Journal of Number Theory, Mathematics Magazine, Natural density, Nicomachus, Number theory, Parity (mathematics), Perfect number, Quasiperfect number, Semiperfect number, Simon Stevin (journal), Weird number.
In number theory, the aliquot sum s(n) of a positive integer n is the sum of all proper divisors of n, that is, all divisors of n other than n itself.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
In number theory, a deficient or deficient number is a number n for which the sum of divisors σ(n) for all sufficiently large n.Sándor et al (2006) p.108.
In mathematics, a divisor of an integer n, also called a factor of n, is an integer m that may be multiplied by some integer to produce n. In this case, one also says that n is a multiple of m. An integer n is divisible by another integer m if m is a divisor of n; this implies dividing n by m leaves no remainder.
In mathematics, and specifically in number theory, a divisor function is an arithmetic function related to the divisors of an integer.
In number theory, friendly numbers are two or more natural numbers with a common abundancy index, the ratio between the sum of divisors of a number and the number itself.
An integer (from the Latin ''integer'' meaning "whole")Integer 's first literal meaning in Latin is "untouched", from in ("not") plus tangere ("to touch").
The book Introduction to Arithmetic (Ἀριθμητικὴ εἰσαγωγή, Arithmetike eisagoge) is the only extant work on mathematics by Nicomachus (60–120 AD).
The Journal of Number Theory is a mathematics journal that publishes a broad spectrum of original research in number theory.
Mathematics Magazine is a refereed bimonthly publication of the Mathematical Association of America.
In number theory, natural density (or asymptotic density or arithmetic density) is one of the possibilities to measure how large a subset of the set of natural numbers is.
Nicomachus of Gerasa (Νικόμαχος; c. 60 – c. 120 AD) was an important ancient mathematician best known for his works Introduction to Arithmetic and Manual of Harmonics in Greek.
Number theory, or in older usage arithmetic, is a branch of pure mathematics devoted primarily to the study of the integers.
In mathematics, parity is the property of an integer's inclusion in one of two categories: even or odd.
In number theory, a perfect number is a positive integer that is equal to the sum of its proper positive divisors, that is, the sum of its positive divisors excluding the number itself (also known as its aliquot sum).
In mathematics, a quasiperfect number is a natural number n for which the sum of all its divisors (the divisor function σ(n)) is equal to 2n + 1.
In number theory, a semiperfect number or pseudoperfect number is a natural number n that is equal to the sum of all or some of its proper divisors.
Simon Stevin was a Dutch language academic journal in pure and applied mathematics, or Wiskunde as the field is known in Dutch.
In number theory, a weird number is a natural number that is abundant but not semiperfect.