6687
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 9672
- Proper Divisor Sum (Aliquot Sum)
- 2985
- 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
- 4452
- Möbius Function
- 0
- Radical
- 2229
- Omega Function (Ω)
- 3
- 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
- 49
- 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
- no
- Odd
- yes
Appears in sequences
- Minimal number of moves for the cyclic variant of the Towers of Hanoi for 3 pegs and n disks, with the final peg one step away.at n=9A005665
- Expansion of 1/((1-3x)(1-6x)(1-8x)(1-10x)).at n=3A028080
- Convolution of natural numbers n >= 1 with Fibonacci numbers F(k), k >= 4.at n=12A033960
- Numbers whose base-9 representation has exactly 5 runs.at n=32A043634
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 99 ).at n=24A063372
- Self-convolution forms A093635.at n=8A093636
- a(1)=1. a(n) = a(n-1) + sum of the triangular numbers which are among the first (n-1) terms of the sequence.at n=22A100963
- Numbers n such that every digit occurs at least once in n^3.at n=18A119735
- Floor((x^n - (1-x)^n)/sqrt(3)+.5) where x = (sqrt(3)+1)/2.at n=29A136422
- Row 2 of array in A144502.at n=5A144495
- Square array read by antidiagonals upwards: T(n,k) is the number of scenarios for the gift exchange problem in which each gift can be stolen at most once, when there are n gifts in the pool and k gifts (not yet frozen) in peoples' hands.at n=33A144502
- G.f.: A(x) = exp( Sum_{n>=1} 3^(n^2) * x^n/n ), a power series in x with integer coefficients.at n=3A155203
- Triangle, read by rows, where g.f.: A(x,y) = exp( Sum_{n>=1} (3^n + y)^n * x^n/n ) is a power series in x and y with integer coefficients.at n=6A155812
- a(n) = (2*n^3 + 5*n^2 + 5*n)/2.at n=17A162267
- Numbers k such that Sum_(i=1..k) prime(i)*(-1)^(i+1) is a square.at n=12A175117
- T(n,k)=Number of arrays of 2n nondecreasing integers in -k..k with sum zero and equal numbers greater than zero and less than zero.at n=58A203291
- Number of arrays of 8 nondecreasing integers in -n..n with sum zero and equal numbers greater than zero and less than zero.at n=7A203294
- Triangle of coefficients of polynomials v(n,x) jointly generated with A209139; see the Formula section.at n=48A209140
- Numbers congruent to 3 in the structure (or curve) of A211000.at n=48A211002
- Number of nX3 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..3 nX3 array.at n=4A220927