5680
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 13392
- Proper Divisor Sum (Aliquot Sum)
- 7712
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2240
- Möbius Function
- 0
- Radical
- 710
- Omega Function (Ω)
- 6
- 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
- 36
- 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
- Symmetries in unrooted (1,3) trees on 2n vertices.at n=10A003610
- Coordination sequence T1 for Zeolite Code SGT.at n=47A008229
- Number of trees on n nodes with 3 forbidden limbs of size 4, 5 and 6.at n=13A014278
- Population of "Triangle" cellular automaton at n-th generation.at n=34A018189
- Number of 3 X 3 matrices with elements from [0,...,(n-1)] satisfying the condition that the middle element of each row or column is the difference of the two end elements (in absolute value).at n=9A058333
- a(n) = (sum of digits of n)^4 - (sum of digits^4 of n).at n=45A069964
- Greedy frac multiples of 1/Pi: a(1)=1, Sum_{n>0} frac(a(n)*x) = 1 at x=1/Pi, where "frac(y)" denotes the fractional part of y.at n=22A080142
- Consider recurrence b(0) = (2n+1)/4, b(n) = b(0)*ceiling(b(n-1)); sequence gives first integer reached (or -1 if no integer is ever reached).at n=33A081851
- Numbers k such that k!!!! + 1 is prime.at n=20A085146
- Indices of primes in sequence defined by A(0) = 43, A(n) = 10*A(n-1) - 27 for n > 0.at n=13A101713
- Index of the first occurrence of A019565(2n-1) in sequence A103790.at n=20A103791
- Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and having sum of the heights of its pyramids equal to k (a pyramid is a sequence u^pd^p or U^pd^(2p) for some positive integer p, starting at the x-axis; p is the height of the pyramid).at n=55A109157
- Sums of squared terms in rows of triangle A112555.at n=9A112556
- Number of n-fold branched coverings of the projective plane with r cyclic branch points (n,r>=1); array read by downward antidiagonals.at n=32A113949
- Triangle read by rows: T(n,k) is the number of hill-free Schroeder paths of length 2n that have k returns to the x-axis (0<=k<=floor(n/2)). A Schroeder path of length 2n is a lattice path from (0,0) to (2n,0) consisting of U=(1,1), D=(1,-1) and H=(2,0) steps and never going below the x-axis. A hill is a peak at height 1.at n=28A114692
- Unsigned row sums of triangle A114700.at n=18A116466
- A129957(n) - n*(n-1)/2.at n=18A129959
- Row sums of triangle A130461.at n=12A130476
- Numbers n where |sinc(n)| decreases monotonically to 0 (where sinc(x)=sin(x)/x).at n=41A131975
- a(1)=1, a(n)=a(n-1)+n^1 if n odd, a(n)=a(n-1)+ n^4 if n is even.at n=7A140146