1858
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2790
- Proper Divisor Sum (Aliquot Sum)
- 932
- 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
- 928
- Möbius Function
- 1
- Radical
- 1858
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 130
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Number of n-node unrooted quartic trees; number of n-carbon alkanes C(n)H(2n+2) ignoring stereoisomers.at n=14A000602
- a(n) = Catalan(n) + Catalan(n+1) - 1.at n=7A000778
- Numbers k such that 33*2^k - 1 is prime.at n=27A002240
- Number of labeled irreducible 2-connected graphs with n edges.at n=2A005643
- Shifts left when inverse Moebius transform applied twice.at n=29A007557
- Coordination sequence T1 for Zeolite Code AFS.at n=33A008023
- Coordination sequence T3 for Zeolite Code ATS.at n=31A008040
- Coordination sequence T1 for Zeolite Code BPH.at n=33A008055
- Year of birth of n-th President of U.S.A.at n=25A008745
- Coordination sequence T4 for Zeolite Code DFO.at n=33A009878
- Coordination sequence T3 for Zeolite Code RSN.at n=28A009887
- Coordination sequence for FeS2-Pyrite, S position.at n=20A009956
- a(0) = 1, a(n) = 29*n^2 + 2 for n>0.at n=8A010019
- Vertex-transitive graphs of valency 10 with n nodes.at n=13A023637
- a(n) = floor(Sum_{1<=i<j<=n} (sqrt(j)-sqrt(i))^2).at n=31A025196
- Squarefree m with no 4k+3 factors such that Pell equation x^2 - m*y^2 = -1 is insoluble.at n=44A031398
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 42.at n=8A031540
- Numbers k such that 253*2^k+1 is prime.at n=27A032503
- Fractional part of square root of a(n) starts with 1: first term of runs.at n=40A034107
- Multiplicity of highest weight (or singular) vectors associated with character chi_61 of Monster module.at n=34A034449