8540
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 20832
- Proper Divisor Sum (Aliquot Sum)
- 12292
- 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
- 2880
- Möbius Function
- 0
- Radical
- 4270
- Omega Function (Ω)
- 5
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 65
- 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
- Expansion of eta(q^10)^12/(eta(q^2)^4*eta(q^5)^8) in powers of q.at n=18A006710
- Irregular triangle read by rows: Whitney numbers of the second kind a(n,k), n >= 1, k >= 0, for the star poset.at n=53A007799
- arcsinh(cos(x)*log(x+1))=x-1/2!*x^2-2/3!*x^3+6/4!*x^4+13/5!*x^5...at n=8A012470
- Fibonacci sequence beginning 0, 14.at n=15A022348
- a(n) = n * Fibonacci(n+1).at n=14A023607
- a(n) = binomial(2*n+6,n+7)*(n^2+7*n+1)/(n+8) = f(n,n+6) where f is given in A034261.at n=5A034273
- Coefficients of the '6th-order' mock theta function rho(q).at n=45A053270
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 91 ).at n=27A063364
- Numbers k such that phi(k) = bigomega(k)*tau(k)^2.at n=17A068540
- Numbers k such that k^2 + k - 1 and k^2 + k + 1 are twin primes and (k + 1)*(k + 1) + k + 1 - 1 and (k + 1)*(k + 1) + k + 1 + 1 are also twin primes.at n=8A088498
- (prime(n)*(prime(n+1)-1) + (prime(n)-1)*prime(n+1)) / 2.at n=22A099909
- Expansion of e.g.f. (1 + y)^(1 + x).at n=58A105793
- Triangle T(n, m) = T(n-1, m-1) + (4m-3)*T(n-1, m) read by rows 1<=m<=n.at n=24A111578
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+16807)^2 = y^2.at n=4A118576
- Numbers k such that k and k^2 together contain all ten digits.at n=25A122477
- Half-sum (or average) of cubes of two distinct odd primes.at n=26A138855
- Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 1, read by rows.at n=31A157210
- Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) - m*f(n,k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1, f(n, k) = k if k <= floor(n/2) otherwise n-k, and m = 1, read by rows.at n=32A157210
- G.f. A(x) satisfies: A(x)^2 = 1/AGM(1, 1 - 8*x/A(x)^2 ).at n=17A158122
- A quadrisection of A158122: a(n) = A158122(4n+1).at n=4A158213