natural number
number in the set of natural numbers, used for counting
almost prime
natural number with a given number of prime factors
fortunate number
named after Reo Fortune
matching number
size of a maximum matching in a graph
edge cover number
size of a minimum edge cover in a graph without isolated vertices
googol
large integer number defined as ten raised to the power of 100
googolplex
large number defined as ten to the power of one googol
practical number
a number such that it and all smaller numbers may be represented as sums of its divisors
Carmichael number
composite number in number theory
lucky number
integer filtered out using a sieve similar to that of Eratosthenes
frugal number
number with more digits than its prime factorization
prime power
positive integer power of a prime number
maximum vertex degree
maximum number of edges that a vertex is adjacent to
perfect number
positive integer which equals the sum of all its divisors
abundant number
number for which the sum of its proper divisors is greater than the number itself
Graham's number
enormously large number, the upper bound solution to a Ramsey theory problem
Bell number
integer sequence counting the possible partitions of a set
Shannon number
lower bound on the game-tree complexity for chess
sequence of Lucas numbers
entire infinite integer series where the next number is the sum of the two preceding it (2, 1, 3, 4, 7, 11, ...)
undulating number
number that has the digit form ababab... in base 10
perfect totient number
Number that is the sum of its iterated totients
superior highly composite number
numeral system
intersection number
smallest number of cliques that together cover all edges
minimum vertex degree
graph property
zero
integer number zero; neutral element for the addition
Jevons' number
natural number
rough number
positive integer with large prime factors
automorphic number
a natural number whose square "ends" in the same digits as the number itself
word length
number of letters, sounds, syllables, or morphemes in a word
probable prime
number that satisfies a given necessary condition for primality
vertex cover number
size of a vertex cover of minimum size
aspiring number
numbers whose aliquot sequence terminates in a perfect number
number of the beast
number associated with the beast in the Book of Revelation; either 666 or 616, depending on the manuscript
Stirling number
important sequences in combinatorics
Fermat number
positive integer of the form (2^(2^n))+1
deficient number
natural integer number for which the sum of its proper strict divisors (other than itself) is less than the number itself
Perrin number
Number sequence 3,0,2,3,2,5,5,7,10,... defined by recurrence relation P(n) = P(n-2) + P(n-3).
Blum integer
Product of two distinct primes ≡ 3 (mod 4)
Woodall number
type of natural number
Smooth number
a number all of whose prime factors are small
Leyland number
a natural number representable in the form x^y + y^x
magic number
number of protons or neutrons that make a nucleus particularly stable
Cullen number
number of the form n*(2^n)+1
sublime number
numbers with a perfect number of factors and a perfect sum of factors
Zuckerman number
numbers that are divisible by the product of their digits (to base 10)