15580
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
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 35280
- Proper Divisor Sum (Aliquot Sum)
- 19700
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5760
- Möbius Function
- 0
- Radical
- 7790
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 84
- 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
- Xcatalans - produced as a self-convolved sequence like Catalan numbers (A000108) but use carryless GF(2)[ X ] polynomial multiplication.at n=10A061922
- a(0) = 1; a(n) = Sum_{1 <= k <= n and k|n} a(n-k).at n=20A067951
- Expansion of (eta(q^3)eta(q^15)/(eta(q)eta(q^5)))^2 in powers of q.at n=22A093065
- Fourth column (m=3) of (1,6)-Pascal triangle A096956.at n=39A096957
- Structured small rhombicosidodecahedral numbers.at n=9A100148
- Period (multiplicative order base 10) of the terms in A116074 and A116075.at n=1A116076
- a(n) = n*(2*n^2 + 5*n + 3).at n=19A163815
- Multiples of 19 whose digit reversal - 1 is also a multiple of 19.at n=37A166399
- Number of words of length n over an alphabet of size 5 which do not contain a run of 5 identical letters.at n=6A188580
- Number of rhombuses on a (n+1)X9 grid.at n=40A190097
- 0-sequence of reduction of hexagonal numbers sequence by x^2 -> x+1.at n=10A192143
- Number of (w,x,y,z) with all terms in {0,...,n} and (least gapsize)<=2.at n=11A212898
- Numbers k such that 3^k + 2^k + 10 is prime.at n=17A219617
- Number of tilings of a 5 X n rectangle using integer-sided square tiles of area > 1.at n=57A226369
- Alternating square row sums of the table A072233 (A008284).at n=31A238313
- 2-dimensional array T(n, k) listed by antidiagonals for n >= 2, k >= 1 giving the number of acyclic paths of length k in the graph G(n) whose vertices are the integer lattice points (p, q) with 0 <= p, q < n and with an edge between v and w iff the line segment [v, w] contains no other integer lattice points.at n=12A247944