4085
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
- 8
- Divisor Sum
- 5280
- Proper Divisor Sum (Aliquot Sum)
- 1195
- 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
- 3024
- Möbius Function
- -1
- Radical
- 4085
- 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
- 51
- 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
- a(n) = a(n-1) + a(n-5); a(0) = ... = a(4) = 1.at n=32A003520
- Expansion of 1/(1 -x^5 -x^6 -x^7 - ...).at n=37A017899
- a(n)-th nonsquarefree is sum of first k nonsquarefrees for some k.at n=42A020644
- Coordination sequence T5 for Zeolite Code CFI.at n=42A033603
- Decimal part of a(n)^(1/7) starts with n so that a(n) < a(n+1).at n=28A034072
- Numbers whose base-4 representation contains exactly two 1's and four 3's.at n=14A045123
- a(n)=T(n,2), array T as in A049735.at n=36A049745
- Number of trees T of order n such that W(T) = W(L(L(T))) where W(G) and L(G) are the Wiener index and line graph of a graph G.at n=25A051175
- Triangle of T(n,k) where T(n,k)/(n-1)! is probability of player k out of n players winning a game of "Elimination": rules are that player 1 chooses one of the others at random to be eliminated, then player 2 (or 3 if player 2 has been eliminated) chooses somebody else at random from the survivors to be eliminated next, then the next surviving player chooses and so on round the circle until all but one have been eliminated.at n=40A071818
- Odd interprimes not divisible by 3.at n=42A072573
- Numbers k such that the k-th term of the EKG sequence (A064413(k)) has more than one controlling prime.at n=16A073735
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=1, r=5, I={0,2,3}.at n=34A079955
- a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + 2*a(n-4).at n=11A084173
- a(n) = -1/16-3*n^2/8+17*n/12+n^3/12+(-1)^n/16.at n=37A088795
- a(n) = 2^(n+1) - n.at n=10A095768
- Expansion of (1-x)^2/((1-x)^3-4x^4).at n=12A097121
- a(n) = 2^(n + 11) - 11.at n=1A098808
- A quadrisection of 1/(1-x-x^5).at n=8A099235
- Sum C(n-4k,k-1), k=0..floor(n/5).at n=36A099562
- a(n) = 2^(2*n)-(2*n-1).at n=6A100102