Multiplicative Identity
Even Prime
Number of Spatial Dimensions We Live In
Number of Colors Sufficient to Color All Planar Maps
Number Of Platonic Solids
Smallest Perfect Number
Smallest Number of Sides of a Polygon that Cannot be Constructed with Straightedge and Compass
Largest Cube in Fibonacci Sequence
Maximum Number of Cubes Needed to Sum Any Integer
Base of Our Number System
Smallest Two-Digit Palindrome
Smallest Abundant Number
Number of Archimedian Solids
Smallest Even that Has No Solution to the Totient Function
Smallest Composite Number n that There is One Group of Order n
Only Number that Has x^y=y^x for x≠y
Number of Wallpaper Groups
Only Positive Number that is Twice the Sum of its Digits
Maximum Number of Fourth Powers to Sum Any Number
Number of Rooted Trees with Six Vertices
Smallest Number of Distinct Squares Needed to Tile a Square
Number of Partitions of 8
Smallest Number of Integer-Side Boxes that Tile a Box So that No Two Boxes Share a Common Length
Largest Number Divisible by All Numbers Less Than its Square Root
Smallest Square that is the Sum of Two Squares
Directly Between a Square and a Cube
Largest Number that is the Sum of the Digits of its Cube
Only Perfect Number with Two Digits
Seventh Lucas Number
Largest Number that All Numbers Relatively Prime to it are Prime
Mersenne Prime of 2^5
Smallest Non-Trivial Fifth Power
Largest Number that is not a Sum of Distinct Triangular Numbers
Smallest Number With Property that it and Its Neighbors Have an Equal Amount of Divisors
Number of Hexominoes
Smallest Non-Trivial Number that is a Triangular Square
Maximum Number of Fifth Powers Needed to Sum any Number
Last Roman Numeral Written Lexicographically
Smallest Number that has Three Partitions into Three Parts that have the Same Product
Only Number Whose Letters are in Alphabetical Order
Sum of First Six Primes
The Answer to the Ultimate Question of Life, the Universe, and Everything
Number of One-Sided 7-iamonds
Number of Derangements of Five Items
Third Kaprekar Number
Number of Distinct Arrangements of Non-Attacking Queens on a 9x9 Chessboard
Largest Number of Cubes that Cannot Tile a Cube
Smallest Number with Ten Divisors
Smallest Number that it and its Neighbors are Squareful
Smallest Number that can be Written as the Sum of Squares in Two Ways
Sixth Motzkin Number
Fifth Bell Number
Only Two-Digit Number that is Reversed in Hexadecimal
Smallest Number that can be Written as the Sum of Three Squares in Three Ways
Largest Triangular Number in Fibonacci Sequence
Number of Reduced 5x5 Latin Squares
111 in Base 7
Number of Communative Semigroups of Order 4
Number of Stellations of an Icosahedron
Smallest Number Divisible by 1-6
Third Secant Number
Smallest Number that can be Written as the Sum of Three Distinct Squares in Two Ways
Number of Partially Ordered Sets of Five Elements
Smallest Number with Seven Divisors
Smallest Number that Becomes a Square if its Reverse is Added or Subtracted from It
Number of 8-iamonds
Smallest Number that is Palindromic in Bases 5 and 6
Last Two-Digit String that Appears in Pi
Smallest Number Written with Distinct, Congruent Digits
Smallest Weird Number
Smallest Number > 60 that Divides into the Sum of the Primes Less Than It
Smallest Non-Square Number Whose Square Root Has a Six Outside the Radical
Smallest Multi-Digit Number that is One Less than Twice its Reverse
Number of non-Hamiltonian Polyhedra with a Minimum Number of Vertices
Number of Orderings of 4 Objects with Ties Allowed
Fifth 1-Automorphic Number
Largest Number that Cannot be Written as Sum of Numbers Whose Reciprocals Sum to One
Smallest Number that can be Written as Sum of Four Distinct Squares in Three Ways
Largest Number < 80 Whose Digits Form an Arithmetic Sequence
Smallest Number n Where n and n+1 are Both Products of Four or More Primes
Smallest Non-Trivial Number that is the Square of the Sum of Its Digits
Number of 6-Hexes
Number of Strongly Connected Digraphs with Four Vertices
Largest Order of a Permutation with Fourteen Elements
Largest n for Which 1^2+2^2+3^2...+n^2=1+2+3...+m Has a Solution
222 in Base 6
Sum of Squares of First Four Primes
Smallest Number Whose Square has no Isolated Digits
8^1+9^2
Number of Degrees in a Right Angle
Smallest Pseudoprime in Base 3
Number of Different Arrangements of Eight Non-Attacking Queens on an 8x8 Chessboards
333 in Base 5
Sixth Smith Number
Number of Planar Partitions of 10
Smallest Number that can be Written as Difference of Two Squares in Four Ways
Smallest Number Such that its First Three Multiples Contain the Digit Nine
Smallest Number Such that its First Five Multiples Contain the Digit Nine
Largest Two-Digit Number
Smallest Square that is the Sum of Four Consecutive Cubes