1836
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 5040
- Proper Divisor Sum (Aliquot Sum)
- 3204
- 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
- 576
- Möbius Function
- 0
- Radical
- 102
- Omega Function (Ω)
- 6
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 130
- 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
- a(n) = n^2*Product_{p|n} (1 + 1/p).at n=33A000082
- Convolved Fibonacci numbers.at n=9A001628
- Expansion of e.g.f. 1/(4 - exp(x) - exp(2*x) - exp(3*x)).at n=3A004701
- Number of distinct autocorrelations of binary words of length n.at n=46A005434
- a(n) = n*(5*n+1)/2.at n=27A005475
- Least k such that binomial(k,n) has n or more distinct prime factors.at n=38A005733
- Unique period lengths of primes mentioned in A007615.at n=40A007498
- Coordination sequence T3 for Zeolite Code HEU.at n=28A008118
- Coordination sequence T3 for Zeolite Code NON.at n=26A008214
- Coordination sequence T1 for Zeolite Code STI.at n=29A008234
- Theta series of direct sum of 3 copies of hexagonal lattice.at n=8A008654
- Expansion of g.f.: x^4/((1-x)*(1-x^2)^2*(1-x^3)).at n=51A008763
- "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=23A009550
- Coordination sequence T4 for Zeolite Code iRON.at n=30A009884
- Coordination sequence T2 for Zeolite Code ZON.at n=30A009920
- Aliquot sequence starting at 660.at n=2A014362
- Number of intersection points of diagonals of an n-gon in general position, plus number of vertices.at n=16A014626
- Powers of fifth root of 18 rounded up.at n=13A018167
- a(1)=3; for n>1, a(n) is smallest positive integer such that a(1)^2+...+a(n)^2 = m^2 for some m.at n=6A018930
- a(n) = 2*a(n-1) + 2*a(n-2) - 3*a(n-3), with a(0) = 2, a(1) = 5, a(2) = 12.at n=8A019485