2688
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 8160
- Proper Divisor Sum (Aliquot Sum)
- 5472
- 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
- 768
- Möbius Function
- 0
- Radical
- 42
- Omega Function (Ω)
- 9
- 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
- 14
- Smith Number
- yes
- 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
- Generalized class numbers c_(n,1).at n=30A000233
- Expansion of (Product_{j>=1} (1-(-x)^j) - 1)^8 in powers of x.at n=17A001486
- Glaisher's function V(n).at n=20A002611
- 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=23A002706
- Low-temperature series in exp(4J/kT) for antiferromagnetic susceptibility for the Ising model on square lattice.at n=7A002979
- Number of directed Hamiltonian cycles (or Gray codes) on n-cube.at n=3A003042
- a(n) = n^2*(n+1)*(n+2)^2/6.at n=6A004256
- Coefficients of Chebyshev T polynomials: a(n) = A053120(n+12, n), n >= 0.at n=4A006976
- Coordination sequence T5 for Zeolite Code NON.at n=31A008216
- Theta series of {D_7}* lattice.at n=23A008423
- Theta series of {D_7}^{+} packing.at n=31A008435
- Expansion of e.g.f.: exp(tan(x))/cos(x).at n=7A009244
- Expansion of e.g.f. sinh(tan(x))/cos(x), odd powers only.at n=3A009607
- Coordination sequence T3 for Zeolite Code -ROG.at n=39A009861
- tan(arctanh(x)*tanh(x))=2/2!*x^2+400/6!*x^6+2688/8!*x^8...at n=4A012755
- Terms of A001273 with trailing 9's stripped (at n=13 term becomes periodic with period 49).at n=21A018785
- Terms of A001273 with trailing 9's stripped (at n=13 term becomes periodic with period 49).at n=55A018785
- Terms of A001273 with trailing 9's stripped (at n=13 term becomes periodic with period 49).at n=22A018785
- Let sigma_m (n) be result of applying sum-of-divisors function m times to n; call n (m,k)-perfect if sigma_m (n) = k*n; sequence gives the (4,k)-perfect numbers.at n=35A019293
- Number of divisors of A019505(n).at n=39A020697