17180
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 36120
- Proper Divisor Sum (Aliquot Sum)
- 18940
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6864
- Möbius Function
- 0
- Radical
- 8590
- Omega Function (Ω)
- 4
- 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
- 79
- 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
- Number of partitions in parts not of the form 15k, 15k+3 or 15k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 6 are greater than 1.at n=41A035957
- Number of partitions satisfying 0 < cn(2,5) + cn(3,5).at n=36A039897
- Numbers whose base-7 representation has exactly 6 runs.at n=20A043621
- a(n) = floor(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=1, a(2)=3.at n=39A104803
- Numbers whose anti-divisors sum to a perfect cube.at n=26A109351
- a(n) is the coefficient of x^(2*n-1) in the n-fold self-composition of G(x) = x + G(G(x))^3 = g.f. of A153851.at n=4A153850
- A triangular sequence of polynomial coefficients: {a,b,c,d}={4, 5, 5, 0}; p(x,n)=(-1)^(n)*(1 - d - c x)^(n + 1)*Sum[(a*k + b)^n*(c*x + d)^k, {k, 0, Infinity}].at n=11A154630
- Integers k such that A072473(k) = A072473(k+1) = A072473(k+2) = A072473(k+3).at n=3A255172
- Number of partitions of 2n into exactly 6 parts.at n=32A256310
- Number of partitions of 4n into exactly 6 parts.at n=16A256317
- Number of partitions of 2^n into n parts.at n=6A283111
- G.f. = Phi^5, where Phi = g.f. for A028930.at n=18A328530
- Number of compositions (ordered partitions) of n into distinct parts, the least being 3.at n=40A339164
- Number of ways to write n as an ordered sum of 6 primes (counting 1 as a prime).at n=39A341985
- Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of regions in H_n.at n=19A370978