16428
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 39396
- Proper Divisor Sum (Aliquot Sum)
- 22968
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5328
- Möbius Function
- 0
- Radical
- 222
- Omega Function (Ω)
- 5
- 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
- 40
- 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
- Dirichlet convolution of d(n) (# of divisors) with b_n=2^(n-1).at n=14A034771
- Sorted elements of table (A035002) of a(m,n) = sum(a(m-k,n), k=1..m-1)+sum(a(m,n-k), k=1..n-1).at n=42A035001
- Even numbers n such that 37^2 (the square of the first irregular prime) divides the numerator of Bernoulli(n).at n=30A090789
- a(n) = n * (10*n^2 - 6n + 1) = n * A087348(n).at n=12A104099
- Number of points in the standard root system version of the D_3 (or f.c.c.) lattice having L_infinity norm n.at n=37A110907
- Numbers k such that k * phi(k) is a cube.at n=27A114076
- Numbers m such that m^k does not divide the denominator of the m-th generalized harmonic number H(m,k) nor the denominator of the n-th alternating generalized harmonic number H'(m,k), for k = 5.at n=4A128675
- a(n) = 12*n^2.at n=37A135453
- Number of ways to place 4 nonattacking bishops on an n X n board.at n=5A172127
- Number of monomer-dimer tatami tilings (no four tiles meet) of the n X n grid with n monomers and equal numbers of vertical and horizontal dimers, up to rotational symmetry.at n=18A182107
- Omit the initial 1 from A000141 and take the Mobius transform.at n=36A190622
- a(n) = A182107(4n).at n=4A226300
- Number of nondecreasing -2..2 vectors of length n whose dot product with some nonincreasing -2..2 vector equals n.at n=27A226393
- Smallest multiple of n such that, when expressed in binary, in the string of bits the binary representation of n occurs after the n-1 most significant bits.at n=11A245470
- Number of signed permutations of length n that are sortable to the identity permutation by some sequence of cdr (context-directed reversal) and cds (context-directed swap) moves.at n=5A260506
- Number of n X 3 integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.at n=6A266096
- T(n,k)=Number of nXk integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.at n=42A266101
- Number of 7Xn integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.at n=2A266107
- Molien series for invariants of finite Coxeter group A_9.at n=58A266778
- Number of n X 5 0..2 arrays with every repeated value in every row not one larger and in every column one larger mod 3 than the previous repeated value, and upper left element zero.at n=1A268090