16604
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 33264
- Proper Divisor Sum (Aliquot Sum)
- 16660
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 7104
- Möbius Function
- 0
- Radical
- 8302
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 97
- 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
- Number of permutations that are n-3 "block reversals" away from 12...n.at n=5A007974
- a(n) = A026681(2n,n).at n=7A026682
- T(n,[ n/2 ]), T given by A026681.at n=14A026687
- Distinct even numbers in the numerators of the 1/3-Pascal triangle (by row).at n=33A046559
- Distinct even numbers in writing first numerator and then denominator of each element to the right of the central elements of the 1/3-Pascal triangle (by row).at n=28A046562
- Numbers k such that k^10 == 1 (mod 11^4).at n=11A056094
- The next smallest pair of numbers is taken so that a(2n-1)/a(2n) converges to Pi.at n=33A057082
- Denominators of convergents to Pi by Farey fractions.at n=14A063673
- Numbers n such that sigma(n+1)-sigma(n) = -sigma(n)/d(n), where d(n) denotes the number of divisors of n.at n=6A066177
- Number of solutions to n^2 < x^2 + y^2 + z^2 < (n+1)^2; number of lattice points between spheres of radii n and n+1.at n=36A078184
- Number of permutations of 1..n with displacements restricted to {-7,-6,-5,-4,-3,-2,0,1}.at n=18A189600
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having three distinct values for every i<=n and j<=n.at n=10A211459
- Records in A224796.at n=31A224719
- Number n such that the sum of its proper evil divisors (A001969) equals n.at n=24A230587
- Total number of corners in all partitions of n. A corner of a partition is a point of degree two in the corresponding Ferrers diagram.at n=25A265258
- a(n) = Sum_{k=0..7} (n + k)^2.at n=42A276026
- Irregular triangle read by rows: T(n,k) = number of size k subsets of S_n that remain unchanged under the operation of replacing a permutation with its inverse.at n=26A277081
- Triangle read by rows: T(n, k) = number of permutations that are k "block reversals" away from 12...n, for n >= 0, and (for n>0) 0 <= k <= n-1.at n=34A300003
- E.g.f. satisfies A(x) = -log(1 - x) * exp(2 * A(x)).at n=5A357333