15796
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 30240
- Proper Divisor Sum (Aliquot Sum)
- 14444
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7160
- Möbius Function
- 0
- Radical
- 7898
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 40
- 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
- McKay-Thompson series of class 6D for Monster.at n=18A007257
- McKay-Thompson series of class 6D for Monster with a(0) = 1.at n=18A045487
- Larger members of g-reduced amicable pairs a < b such that sigma(a) = sigma(b) = a + b + gcd(a,b).at n=34A054572
- Numbers n such that 5*10^n-1 is prime.at n=14A056712
- Triangle read by rows: T(n,k) is the number of binary sequences of length n containing k subsequences 0101 (n,k>=0).at n=51A118869
- Number of binary sequences of length n with no subsequence 0101.at n=15A118870
- McKay-Thompson series of class 6D for the Monster group with a(0) = -4.at n=18A121667
- Number of graphs on n labeled nodes with degree at most 2.at n=7A136281
- Derived from the centered polygonal numbers: start with the first triangular number, then the sum of the first square number and the second triangular number, then the sum of first pentagonal number, the second square number and the third triangular number, and so on and so on...at n=22A141534
- Arises in combinatorial approach to the power of 2 in the number of involutions.at n=14A157253
- Number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.at n=26A188250
- Number of rooted fullerenes with n faces, where "rooted" means that one triple (v,e,f) is distinguished, where v is a vertex, e is an edge on that vertex and f is a face on that edge.at n=12A203977
- Left inverse of A277558.at n=58A277578
- a(n) = n*(1-3n+2*n^2+2*n^3)/2.at n=11A277977
- Number of partitions of n such that the (sum of distinct odd parts) >= n/2.at n=43A284615
- a(1) = number of 1-digit primes (that is, 4: 2,3,5,7); then a(n) = number of distinct n-digit prime numbers obtained by left- or right-concatenating a digit to the a(n-1) primes obtained in the previous iteration.at n=13A298048
- G.f. A(x) satisfies: 1 = A(x) - x*A(x)^2/(A(x) - x*A(x)^3/(A(x) - x*A(x)^4/(A(x) - x*A(x)^5/(A(x) - x*A(x)^6/(A(x) - ...))))), a continued fraction relation.at n=8A338752
- Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = (n!)^k * Sum_{j=1..n} (1/j!)^k.at n=39A343863
- Number of edges in the directed graph for the Reversed Zeckendorf game with starting number n.at n=46A389617