6720
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 56
- Divisor Sum
- 24384
- Proper Divisor Sum (Aliquot Sum)
- 17664
- 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
- 1536
- Möbius Function
- 0
- Radical
- 210
- Omega Function (Ω)
- 9
- 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
- 44
- 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
- Red rooted red-black trees with n internal nodes.at n=15A001138
- a(n) = n!/6.at n=5A001715
- Expansion of (theta_3(z)*theta_3(7z)+theta_2(z)*theta_2(7z))^3.at n=31A002653
- Theta series of 6-dimensional lattice A_6^(2) (other names for this lattice or the corresponding quadratic form are LAMBDA_{3,lambda}, P_6^(5), phi_6, F_14).at n=31A002706
- Smallest number with 2n divisors.at n=27A003680
- Expansion of Eisenstein series E_4(q) (alternate convention E_2(q)); theta series of E_8 lattice.at n=3A004009
- Theta series of D_5 lattice.at n=27A005930
- Theta series of D_5 lattice.at n=31A005930
- State assignments for n-state machine.at n=6A007041
- State assignments for n-state machine.at n=5A007041
- Expansion of critical exponent for walks on tetrahedral lattice.at n=10A007181
- Smallest k such that sigma(x) = k has exactly n solutions.at n=28A007368
- The minimal numbers: sequence A005179 arranged in increasing order.at n=35A007416
- Triangle T(n,k) = n!/(n-k)! (0 <= k <= n) read by rows, giving number of permutations of n things k at a time.at n=41A008279
- Pisot sequence T(4,6), a(n) = floor(a(n-1)^2/a(n-2)).at n=27A020747
- Pisot sequence T(6,9), a(n) = floor(a(n-1)^2/a(n-2)).at n=26A020751
- a(n) = n*(11*n - 1)/2.at n=35A022268
- Theta series of A*_8 lattice.at n=27A023920
- Partial products of the sequence of prime powers (A000961).at n=6A024923
- a(n) = 10*(n+1)*binomial(n+3,5)/3.at n=5A027790