8115
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13008
- Proper Divisor Sum (Aliquot Sum)
- 4893
- 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
- 4320
- Möbius Function
- -1
- Radical
- 8115
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 114
- 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
- G.f.: 1/((1-4x)(1-11x)(1-12x)).at n=3A019752
- a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-1)*a(1) for n >= 5, with initial values 1,1,1,1.at n=11A025268
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 12.at n=15A031690
- a(n+1) = a(n)-th composite number, with a(1) = 11.at n=29A059407
- Zero, together with positive numbers k such that prime(k) + k is a square.at n=29A064371
- Harshad numbers which terminate in their digital sum.at n=46A070938
- Numbers n such that ((n-1)^2+1)/2 and n^2+1 and ((n+1)^2+1)/2 are prime if n is even or (n-1)^2+1 and (n^2+1)/2 and (n+1)^2+1 are prime if n is odd.at n=39A082612
- Multiples of 3 in which there is no common digit in successive terms.at n=25A083491
- Third column (m=4) of array A090452.at n=14A090453
- If mod(n,3)=0 then a(n) = a(n-1), if mod(n,3)=1 then a(n) = Q(n-2)+Q(n-3), if mod(,n,3)=2 then a(n-3)+a(n-4)+a(n-5), where Q() = A005185().at n=44A102149
- If mod(n,3)=0 then a(n) = a(n-1), if mod(n,3)=1 then a(n) = Q(n-2)+Q(n-3), if mod(,n,3)=2 then a(n-3)+a(n-4)+a(n-5), where Q() = A005185().at n=45A102149
- Numbers n such that prime(n) + n is a perfect power.at n=34A107605
- Multiples of 15 containing a 15 in their decimal representation.at n=39A121035
- Numbers k such that the absolute value of 14^k - k^14 is prime.at n=7A128454
- Coefficients of a Ramanujan q-series.at n=27A143184
- Sum of proper divisors minus the number of proper divisors of the perfect number A000396(n).at n=3A154896
- a(n) = 36*n^2 + n.at n=14A157324
- a(n) = 225*n^2 + 15.at n=6A158557
- Number of (w,x,y,z) with all terms in {1,...,n} and 3w = x + y + z + n + 1.at n=31A212251
- Number of tilings of a 4 X n rectangle using L tetrominoes and 2 X 2 tiles.at n=10A226322