16995
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 29952
- Proper Divisor Sum (Aliquot Sum)
- 12957
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8160
- Möbius Function
- 1
- Radical
- 16995
- Omega Function (Ω)
- 4
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 128
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Numbers n for which there are exactly four k such that n = k + reverse(k).at n=39A072428
- Column 0 of triangle A118032, where column 0 of the matrix square of A118032 forms a bisection of this sequence.at n=21A118033
- Triangle T, read by rows, equal to a diagonal bisection of A118032 such that diagonal n of T equals diagonal 2n+1 of A118032: T(n,k) = A118032(2n+1-k,k); also equals the matrix product of A118032 and SHIFT_UP(A118032).at n=55A118045
- Column 0 of triangle A118045; also equals a bisection of A118033, which is column 0 of A118032.at n=10A118046
- Inverse binomial transform of A026641; binomial transform of A127361.at n=11A127328
- Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 5 ones in any 5 X 5 X 5 subtriangle.at n=10A153944
- Triangle T(n, k) = coefficients of p(x, n) where p(x,n) = (x+1)*p(x, n-1) + n*(n-1)*x*p(x, n-2), read by rows.at n=31A154986
- Triangle T(n, k) = coefficients of p(x, n) where p(x,n) = (x+1)*p(x, n-1) + n*(n-1)*x*p(x, n-2), read by rows.at n=32A154986
- Coefficient of x in the reduction by (x^2 -> x+1) of the polynomial C(n)*x^n, where C=A022095.at n=10A192917
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 353", based on the 5-celled von Neumann neighborhood.at n=29A271307
- G.f.: A(x) = exp( Sum_{n>=1} x^n/n * (1 + x^n*A(x)^(2*n)) / (1 + x^n*A(x)^n) ).at n=14A307231
- a(1) = 50 and for any n > 0, a(n+1)^2 is the smallest square that begins with a(n).at n=26A309123
- Number of labeled simple graphs with n vertices whose covered portion has exactly two automorphisms.at n=6A330345