5778
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 12960
- Proper Divisor Sum (Aliquot Sum)
- 7182
- 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
- 1908
- Möbius Function
- 0
- Radical
- 642
- 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
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- Lucas Number
- yes
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 142
- 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
- Lucas numbers (beginning with 1): L(n) = L(n-1) + L(n-2) with L(1) = 1, L(2) = 3.at n=17A000204
- a(n) = a(n-1)*(a(n-1)^2 - 3).at n=2A001999
- a(n) = round(n*phi^18), where phi is the golden ratio, A001622.at n=1A004953
- a(n) = ceiling(n*phi^18), where phi is the golden ratio, A001622.at n=1A004973
- a(n) = 3*a(n-2) - a(n-4), a(0)=2, a(1)=1, a(2)=3, a(3)=2. Alternates Lucas (A000032) and Fibonacci (A000045) sequences for even and odd n.at n=18A005247
- Bisection of Lucas numbers: a(n) = L(2*n) = A000032(2*n).at n=9A005248
- a(n) = L(L(n)), where L(n) are Lucas numbers A000032.at n=6A005371
- Number of points on surface of octahedron; also coordination sequence for cubic lattice: a(0) = 1; for n > 0, a(n) = 4n^2 + 2.at n=38A005899
- A007824(n)/16.at n=7A007823
- Coordination sequence T3 for Zeolite Code MEP.at n=45A008159
- Coordination sequence for C_3 lattice: a(n) = 16*n^2 + 2 (n>0), a(0)=1.at n=19A010006
- a(n) = prime(n)*(prime(n+1)-1)/2.at n=27A014303
- Even Lucas numbers: a(n) = L(3*n).at n=6A014448
- a(n) = 2*n*(4*n - 1).at n=27A014635
- Numbers n such that n divides n-th Lucas number A000032(n).at n=9A016089
- Number of maximum matchings in the n-Moebius ladder M_n.at n=18A020878
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n+1-k), where k = floor((n+1)/2), s = (Lucas numbers), t = A023533.at n=51A024476
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=28A024844
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n-k+1), where k = floor(n/2), s = A000032, t = A023533.at n=50A025096
- a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026714.at n=5A027202