8542
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12816
- Proper Divisor Sum (Aliquot Sum)
- 4274
- 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
- 4270
- Möbius Function
- 1
- Radical
- 8542
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 171
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A000032 (Lucas numbers).at n=14A023861
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (odd natural numbers), t = (primes).at n=23A025117
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 92.at n=7A031590
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 46 ones.at n=29A031814
- a(n) = (n-1)*(n-2)^4 - A028294(n), for n > 4, with a(1) = a(2) = 0, a(3) = 2, and a(4) = 48.at n=8A075690
- Number of squares on infinite half chessboard at <=n knight moves from a fixed point on the edge.at n=35A098498
- Similar to A072921 but starting with 2.at n=38A152231
- Related to construction of recursive sequences in GF(3^n).at n=4A198312
- Number of rooted trees with n nodes, where cycles are allowed instead of subtrees.at n=12A213674
- Numbers n such that n^16+1 and (n+2)^16+1 are both prime.at n=16A217991
- Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..2 n X 2 array.at n=16A219167
- Number of (n+2) X (6+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 1 and no antidiagonal sum 2 and no row sum 0 and no column sum 3.at n=37A255799
- Arrange the base 10 digits of the n-th Fibonacci number in descending order.at n=18A273003
- Largest integer that cannot be represented as x1^2 + ... + xk^2, where k >= 1, n <= x1 < ... < xk, and 1/x1 + ... + 1/xk = 1.at n=0A297896
- Largest integer that cannot be represented as x1^2 + ... + xk^2, where k >= 1, n <= x1 < ... < xk, and 1/x1 + ... + 1/xk = 1.at n=1A297896
- Number of free trees of n vertices whose automorphisms are a 2-group.at n=16A309352