12178
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18270
- Proper Divisor Sum (Aliquot Sum)
- 6092
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6088
- Möbius Function
- 1
- Radical
- 12178
- 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
- 63
- Smith Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- a(0)=1, a(1)=1, a(2)=1, a(n) = 2*a(n-1) + a(n-2) + 1.at n=12A033539
- Consider the recursion b(1,n) = 1, b(k+1,n) = b(k,n) + (b(k,n) reduced mod(k+n)); then there is a number x such that b(k,n) - b(k-1,n) is a constant x depending only on n, for k > y = A074483(n). Sequence gives values of x.at n=36A074482
- Consider the recursion b(1,n) = 1, b(k+1,n) = b(k,n) + (b(k,n) reduced mod(k+n)); then there is a number x such that b(k,n) - b(k-1,n) is a constant x depending only on n, for k > y = A074483(n). Sequence gives values of x.at n=37A074482
- Take a squarefree semiprime and take the difference of its prime factors. If it is a squarefree semiprime repeat the process. Sequence lists the squarefree semiprimes that generate other squarefree semiprimes only in the first k steps of this process. Case k = 4.at n=22A296811
- Expansion of (1 + 3*x - 2*x^2)/(1 - 7*x + 7*x^2 - x^3).at n=5A301383
- Matula-Goebel numbers of unlabeled rooted identity RPMG-trees, meaning the Matula-Goebel numbers of the branches of any non-leaf node are relatively prime.at n=15A316469
- Matula-Goebel numbers of semi-lone-child-avoiding rooted identity trees.at n=35A331963
- Matula-Goebel tree number of tree n with a new leaf added below each existing vertex.at n=40A348067
- Array read by antidiagonals: T(n,k) is the number of sets of k integer sided cuboids with distinct volumes that fill an n X n X n cube.at n=72A387121