6600
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 22320
- Proper Divisor Sum (Aliquot Sum)
- 15720
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1600
- Möbius Function
- 0
- Radical
- 330
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 137
- 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
- a(n) = Sum_{k=0..2} (n+k)! * C(2,k).at n=6A001344
- Number of coprime chains with largest member prime(n).at n=27A003140
- Number of n-step walks on square lattice in the first quadrant which finish at distance n-3 from the x-axis.at n=21A005564
- a(n) = denominator of Bernoulli(2n)/(2n).at n=9A006953
- Theta series of A_5 lattice.at n=42A008445
- a(n) = 2*(n+1)*binomial(n+2,4).at n=7A027777
- a(n) = 4*(n+1)*binomial(n+2,8).at n=3A027781
- Four times second pentagonal numbers: a(n) = 2*n*(3*n+1).at n=33A033580
- Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-3)/3.at n=34A048037
- E.g.f.: (1-x)^2/(1-3*x+x^2).at n=5A052567
- Triangle T(n,k) (n >= 1, 0<=k<=n) giving number of preferential arrangements of n things beginning with k (transposed, then read by rows).at n=23A054255
- Numbers k such that k | sigma_5(k).at n=35A055709
- Numbers k such that sigma(x) = k has exactly 6 solutions.at n=28A060662
- Numbers k such that sigma(k^2 + 1) == 0 (mod k).at n=28A067719
- a(n) = Z(S_m; sigma[1](n), sigma[2](n),..., sigma[m](n)) where Z(S_m; x_1,x_2,...,x_m) is the cycle index of the symmetric group S_m and sigma[k](n) is the sum of k-th powers of divisors of n; m=3.at n=14A068020
- Numbers n such that n*tau(n)>prime(4*n) where tau(n)=A000005(n).at n=23A068352
- Numbers k such that k+1 is composite and divides 3^k-2^k.at n=16A068410
- Barriers for bigomega(n): numbers n such that, for all m < n, m + bigomega(m) <= n.at n=35A068597
- Number of compositions (ordered partitions) of n that are concave-down sequences.at n=47A070211
- Numbers k such that k*rev(k) is a square different from k^2, where rev=A004086, decimal reversal.at n=28A070760