16105
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19332
- Proper Divisor Sum (Aliquot Sum)
- 3227
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12880
- Möbius Function
- 1
- Radical
- 16105
- Omega Function (Ω)
- 2
- 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
- 45
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- Number of rotationally symmetric polyominoes with n cells (that is, polyominoes with exactly the symmetry group C_2 generated by a 180-degree rotation).at n=18A006747
- For any circular arrangement of 0..n-1, let S = sum of squares of every sum of two contiguous numbers; then a(n) = # of distinct values of S.at n=45A007773
- Numbers k that divide s(k), where s(1)=1, s(j)=11*s(j-1)+j.at n=12A014858
- q-Fibonacci numbers for q=11, scaling a(n-2).at n=5A015469
- a(n) = (11^(n+1) - 1)/10.at n=4A016123
- Cyclotomic polynomials at x=11.at n=5A019329
- Cyclotomic polynomials at x=-11.at n=10A020510
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 11.at n=16A022175
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 11.at n=19A022175
- Numbers k such that k^2 is palindromic in base 11.at n=31A029996
- Numbers whose set of base-11 digits is {1,4}.at n=30A032823
- Numbers whose set of base-11 digits is {1,3}.at n=30A032918
- Numbers whose set of base-11 digits is {1,2}.at n=30A032931
- Sums of distinct powers of 11.at n=31A033047
- Number of sublattices of index n in generic 5-dimensional lattice.at n=10A038992
- Number of partitions satisfying cn(0,5) + cn(2,5) <= cn(1,5) and cn(0,5) + cn(2,5) <= cn(4,5) and cn(0,5) + cn(3,5) <= cn(1,5) and cn(0,5) + cn(3,5) <= cn(4,5).at n=47A039883
- a(n) in base 11 is a repdigit.at n=41A048335
- a(n) = n^4 + n^3 + n^2 + n + 1.at n=11A053699
- 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=4.at n=10A068021
- Value of n-th cyclotomic polynomial at the n-th prime.at n=4A070522