8728
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 16380
- Proper Divisor Sum (Aliquot Sum)
- 7652
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4360
- Möbius Function
- 0
- Radical
- 2182
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 47
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Expansion of log(1+x)*log(1+tanh(x)).at n=8A009423
- Related to number of irreducible stick-cutting problems.at n=18A022541
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 23.at n=34A031521
- Multiplicity of highest weight (or singular) vectors associated with character chi_95 of Monster module.at n=38A034483
- Number of partitions of n such that cn(3,5) <= cn(0,5) = cn(1,5) <= cn(2,5) = cn(4,5).at n=69A036865
- Let Py(n)=A000330(n)=n-th square pyramidal number. Consider all integer triples (i,j,k), j >= k>0, with Py(i)=Py(j)+Py(k), ordered by increasing i; sequence gives j values.at n=38A053720
- Numbers beginning and ending with their multiplicative digital root.at n=46A064704
- Take pairs (x,y) with Sum_{j = x..y} j = concatenation of x and y. Sort pairs on y then x. This sequence gives y of each pair.at n=19A070153
- Number of palindromic and unimodal compositions of n. Equivalently, the number of orbits under conjugation of even nilpotent n X n matrices.at n=53A096441
- Bisection of A096441.at n=27A096967
- Records in A119451.at n=15A119452
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, -1), (1, 0)}.at n=7A151297
- Numbers k such that there are 2 primes between 100*k and 100*k + 99.at n=23A186394
- Number of 3-step knight's tours on an (n+2) X (n+2) board summed over all starting positions.at n=12A186852
- Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant in {-1,0,1}.at n=29A209993
- Number of steps to reach 0 when starting from 2^n and iterating the map x -> x - (number of 1's in binary representation of x): a(n) = A071542(2^n) = A218600(n)+1.at n=16A213710
- Smallest number that is the largest value in the Collatz (3x + 1) trajectories of exactly n initial values. (a(n)=0 if no such number exists.)at n=21A233293
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 377", based on the 5-celled von Neumann neighborhood.at n=49A271461
- Number of nX3 0..1 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=7A280156
- T(n,k)=Number of nXk 0..1 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=47A280161