8569
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10080
- Proper Divisor Sum (Aliquot Sum)
- 1511
- 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
- 7200
- Möbius Function
- -1
- Radical
- 8569
- Omega Function (Ω)
- 3
- 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
- 78
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Expansion of e.g.f. exp(x)*(1 + tan(x))/(1 - tan(x)).at n=6A000834
- Centered dodecahedral numbers.at n=9A005904
- Number of homogeneous primitive partition identities with largest part n.at n=9A007343
- Shifts 2 places left under binomial transform.at n=11A007476
- "Pascal sweep" for k=10: draw a horizontal line through the 1 at C(k,0) in Pascal's triangle; rotate this line and record the sum of the numbers on it (excluding the initial 1).at n=50A009550
- Expansion of g.f. x/(1 - 9*x - 8*x^2).at n=5A015584
- Number of ordered triples of integers from [ 2,n ] with no global factor.at n=38A015633
- a(n) = (10*n^3 - 9*n^2 + 2*n)/3 + 1.at n=14A034721
- Composite numbers k, not a power of 2, such that the E(k) == 1 (mod k), where E(k) is the k-th Euler number (A000364).at n=27A035163
- Digitally balanced numbers in both bases 2 and 3.at n=14A049361
- a(n) = 2^n + Fibonacci(n+1).at n=13A052956
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 83 ).at n=30A063356
- Product(n/k - k) where the product is over the divisors k of n and where 1 <= k <= sqrt(n).at n=41A068333
- a(1) = 5; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=46A074340
- Least k such that 10^(2n-1)+k is a brilliant number.at n=41A084476
- a(n+2) = 8*a(n+1) + 21*a(n), with a(1)=1, a(2)=8.at n=4A093103
- a(n) = - a(n-1) - a(n-2) - a(n-3) + 50*(n-4) + 50*a(n-5) + 50*a(n-6) + 50*a(n-7), n >= 8.at n=11A109793
- Apocalypse primes: 10^665+a(n) has 666 decimal digits and is prime.at n=4A115983
- Diagonal sums of the Riordan array A116382.at n=15A116384
- a(n) = 7*n^2 + 14*n + 1.at n=34A131878