6440
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 10840
- 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
- 2112
- Möbius Function
- 0
- Radical
- 1610
- Omega Function (Ω)
- 6
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 23
- 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
- a(n) = round(n*phi^12), where phi is the golden ratio, A001622.at n=20A004947
- a(n) = ceiling(n*phi^12), where phi is the golden ratio, A001622.at n=20A004967
- Number of n-step polygons on Kagome lattice.at n=11A005397
- a(n) = n*(4*n+1).at n=40A007742
- Coordination sequence for D_10 lattice.at n=2A008378
- Theta series of A_7 lattice.at n=6A008447
- Expansion of e.g.f. arctan(log(x+1) - arctan(x)).at n=8A013249
- Expansion of e.g.f. tanh(log(x+1) - arctan(x)).at n=8A013253
- Expansion of e.g.f.: arctan(log(x+1)-tanh(x)).at n=6A013285
- Expansion of e.g.f. tanh(log(x+1) - tanh(x)).at n=8A013289
- Second coordinate of fundamental unit of real quadratic field with discriminant A003658(n), n >= 2.at n=63A014046
- a(n) = (prime(n+2)^2 - 1)/3.at n=31A024700
- Number of triangles a queen can make (starting anywhere) on an n X n board.at n=15A030117
- a(n) = 2*n*(4*n + 3).at n=28A033587
- Absolute value of first differences of A038552, divided by 24.at n=44A038581
- Rhombic matchstick numbers: a(n) = n*(3*n+2).at n=46A045944
- Number of nonempty subsets of {1,2,...,n} in which exactly 3/4 of the elements are <= (n-2)/3.at n=27A048020
- Number of nonempty subsets of {1,2,...,n} in which exactly 3/4 of the elements are <= (n-3)/3.at n=27A048031
- Write fundamental unit for real quadratic field of discriminant n as x + y*omega; sequence gives values of y for n == 1 (mod 4).at n=40A053373
- Triangle T(n,k) of the number of strongly connected digraphs on n labeled nodes and with k arcs, k=0..n*(n-1).at n=31A057273