7208
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 14580
- Proper Divisor Sum (Aliquot Sum)
- 7372
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 3328
- Möbius Function
- 0
- Radical
- 1802
- Omega Function (Ω)
- 5
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 57
- 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
- tan(arcsinh(x)*tan(x))=2/2!*x^2+4/4!*x^4+350/6!*x^6+7208/8!*x^8...at n=4A012613
- arctanh(arcsinh(x)*tan(x))=2/2!*x^2+4/4!*x^4+350/6!*x^6+7208/8!*x^8...at n=4A012618
- Number of 6-valent trees with n nodes.at n=15A036653
- Open 3-dimensional ball numbers (version 4): a(n) is the number of integer points (i,j,k) contained in an open ball of diameter n, centered at (1/2, 1/2, 1/2).at n=24A053596
- Susceptibility series H_4 for 2-dimensional Ising model (divided by 2) for 1 particle excitation.at n=7A055920
- Let u(1)=u(2)=1, u(3)=2n, u(k) = abs(u(k-1)-u(k-2)-u(k-3)) and M(k) = Max_{i<=i<=k} u(i), then for any k >= A078109(n), M(k) = floor(sqrt(k + a(n))).at n=15A078108
- Consider the triangle in which the j-th row begins with prime(j) and is the arithmetic progression with least common difference such that the remaining j-1 terms are composite and not divisible by prime(j). Sequence gives last term in each row.at n=27A095182
- Numbers n such that n^4+1 and n^4+3 are twin primes.at n=44A127871
- Triangle read by rows, T(n, k) = ( ( 6 * Sum_{j=0..k+1} (-1)^j * binomial(n+1, j) * (k-j+1)^n ) - 4 * binomial(n-1, k) ) / 2.at n=24A141696
- a(n) = (2*n + 1)*(5*n + 6).at n=26A153127
- a(n) = 25*n^2 - n.at n=16A157514
- a(n) = 289*n^2 - 17.at n=4A158587
- Numbers k such that k / (A000005(k)*(A000005(k)+1)/2) is an integer.at n=32A160921
- Number of reduced words of length n in the Weyl group D_8.at n=9A162211
- a(n) = prime(n)*T(n), where T = A000217.at n=15A196421
- Numbers m such that 2520*m/k + 1 is a prime for k = 1,...,7.at n=1A208549
- Number of undirected circular permutations i_1,...,i_{n-1} of 1,...,n-1 with i_1-i_2, ..., i_{n-2}-i_{n-1}, i_{n-1}-i_1 pairwise distinct modulo n.at n=10A228762
- Number of Carlitz compositions of n with exactly three descents.at n=10A241693
- Number of length n+2 0..1 arrays with at most one downstep in every n consecutive neighbor pairs.at n=32A255993
- Decimal representation of the n-th iteration of the "Rule 89" elementary cellular automaton starting with a single ON (black) cell.at n=6A267039