2110
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 4
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3816
- Proper Divisor Sum (Aliquot Sum)
- 1706
- 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
- 840
- Möbius Function
- -1
- Radical
- 2110
- 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
- 169
- 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
- yes
- Odd
- no
Appears in sequences
- 2nd differences are periodic.at n=33A002082
- Centered triangular numbers: a(n) = 3*n*(n-1)/2 + 1.at n=37A005448
- Erroneous version of A309982.at n=12A006775
- Erroneous version of A027610.at n=8A007172
- Coordination sequence T4 for Zeolite Code DAC.at n=29A008070
- Coordination sequence T4 for Zeolite Code -CLO.at n=40A009853
- Coordination sequence T3 for Zeolite Code iRON.at n=32A009883
- Representation of n in base of Catalan numbers (a classic greedy version).at n=35A014418
- Numbers k such that the continued fraction for sqrt(k) has period 34.at n=18A020373
- Place where n-th 1 occurs in A023133.at n=36A022795
- Numbers k such that Fibonacci(k) == 55 (mod k).at n=32A023181
- n written in fractional base 5/2.at n=40A024632
- Least m such that if r and s in {1/3, 1/6, 1/9, ..., 1/3n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=20A024838
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = (F(2), F(3), F(4), ... ).at n=11A024861
- a(n) = T(2n,n-1), where T is the array in A026268.at n=5A026295
- a(n) = n-th largest even number in array T given by A027170.at n=36A027183
- The number of Apollonian networks (planar 3-trees) with n+3 vertices.at n=8A027610
- a(n) = (n+3)^2 - 6.at n=43A028878
- Positions of record values in A030747.at n=42A030752
- Numbers whose base-14 expansion has no run of digits with length < 2.at n=22A033027