8648
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 8632
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4048
- Möbius Function
- 0
- Radical
- 2162
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 140
- 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
- Dowling numbers: e.g.f. exp(x + (exp(b*x) - 1)/b), with b=6.at n=5A003578
- Expansion of (1+x^2)/((1-x)^2*(1-x^2)^2).at n=45A005993
- a(n) = n*(n+1)*(2*n+1)/3.at n=23A006331
- Expansion of theta_3 / theta_4.at n=17A007096
- a(n) = floor(n*(n-1)*(n-2)/12).at n=48A011894
- Numbers k such that phi(k + 12) | sigma(k) for k not congruent to 0 (mod 3).at n=31A015850
- Expansion of 1/((1-x)*(1-4*x)*(1-11*x)*(1-12*x)).at n=3A022000
- Define the sequence S(a(0),a(1)) by a(n+2) is the least integer such that a(n+2)/a(n+1) > a(n+1)/a(n) for n >= 0. This is S(3,9).at n=7A022020
- a(n) = 1*(n) + 2*(n-1) + 3*(n-2) + ... + (n+1-k)*k, where k = floor((n+1)/2).at n=45A023855
- a(n) = 1*(n+1-1) + 2*(n+1-2) + ... + k*(n+1-k), where k = floor((n+1)/2).at n=44A023856
- n written in fractional base 10/8.at n=38A024663
- Numbers k that divide sigma(k) + d(k), where d(k) is the number of divisors of k and sigma(k) is their sum.at n=9A056076
- Let R(i,j) be the rectangle with antidiagonals 1; 2,3; 4,5,6; ...; each k is an R(i(k),j(k)) and A057044(n)=j(L(n)), where L(n) is the n-th Lucas number.at n=39A057044
- McKay-Thompson series of class 32A for Monster.at n=35A058629
- Harmonic mean of digits is 6.at n=16A062184
- a(n) = lcm(n, n+1, n+2)/6.at n=45A067046
- Engel expansion of sinh(1/2).at n=23A068379
- Numbers k such that the sum of the non-divisors of k between 1 and k is a perfect square.at n=10A076624
- Numbers k such that sigma(k) + tau(k) = 2k.at n=7A083874
- a(1) = 2, a(n) = a(n-1) + 3*(a(n-1)-floor(a(n-1)^(1/3))^3).at n=19A096295