17906
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 30720
- Proper Divisor Sum (Aliquot Sum)
- 12814
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7668
- Möbius Function
- -1
- Radical
- 17906
- Omega Function (Ω)
- 3
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 141
- 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
- yes
- Odd
- no
Appears in sequences
- a(1) = 7; a(n+1) = a(n)-th nonprime, where nonprimes begin at 0.at n=38A025002
- Interprimes which are of the form s*prime, s=14.at n=28A075289
- Number of compositions (ordered partitions) of n such that some part is repeated consecutively 3 times and no part is repeated consecutively more than 3 times.at n=14A091617
- Number of 3-overlap triangle-free perfect graphs on n nodes.at n=9A123463
- Constant term in the reduction of the polynomial (x+2)^n by x^3->x^2+x+1. See Comments.at n=9A192801
- Number of (w,x,y,z) with all terms in {1,...,n} and w^3>=x^3+y^3+z^3.at n=18A212100
- Total sum of parts of multiplicity 7 in all partitions of n.at n=40A222735
- The number of length n sequences on {0,1,2} such that there are an equal number of 0's and 1's or there are an equal number of 0's and 2's.at n=10A235320
- Number T(n,k) of sequences in {1,...,n}^n with longest increasing subsequence of length k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=23A245667
- Number of sequences in {1,...,n}^n with longest increasing subsequence of length two.at n=4A268869
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 126", based on the 5-celled von Neumann neighborhood.at n=39A270215
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 310", based on the 5-celled von Neumann neighborhood.at n=35A271198
- Triangle of scaled 1-tiered binomial coefficients, T(n,k) = 2^(n+1)*(n-k,k)_1 (n >= 0, 0 <= k <= n), where (N,M)_1 is the 1-tiered binomial coefficient.at n=41A308737
- Number of even-length integer partitions of n with integer alternating product.at n=48A347704