1848
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 5760
- Proper Divisor Sum (Aliquot Sum)
- 3912
- 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
- 480
- Möbius Function
- 0
- Radical
- 462
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
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
- Euler's "numerus idoneus" (or "numeri idonei", or idoneal, or suitable, or convenient numbers).at n=64A000926
- Expansion of (1+x^3)/((1-x)*(1-x^2)^2*(1-x^3)).at n=38A001973
- Theta series of 6-dimensional lattice A_6^(2) (other names for this lattice or the corresponding quadratic form are LAMBDA_{3,lambda}, P_6^(5), phi_6, F_14).at n=16A002706
- Discriminants of the known imaginary quadratic fields with 1 class per genus (a finite sequence).at n=60A003644
- Expansion of (1+2*x+x^2)/(1-42*x+x^2).at n=2A004295
- a(n) = n*(n+2) = (n+1)^2 - 1.at n=42A005563
- a(n) = floor(phi*a(n-1)) + a(n-2) where phi is the golden ratio.at n=10A005830
- Jordan function J_2(n) (a generalization of phi(n)).at n=42A007434
- Expansion of e.g.f. sinh(tan(x))*exp(x).at n=7A009605
- Coordination sequence T1 for Zeolite Code -WEN.at n=31A009862
- Coordination sequence T2 for Zeolite Code -WEN.at n=31A009863
- a(n) = floor( n*(n-1)*(n-2)/5 ).at n=22A011887
- [ n(n-1)(n-2)(n-3)/13 ].at n=14A011923
- Numbers k such that the periodic part of the continued fraction for sqrt(k) contains a single 1.at n=49A013648
- Positive nonsquare integers k such that each term of the regular continued fraction of sqrt(k) divides k.at n=41A013654
- Super-3 Numbers (3n^3 contains substring '333' in its decimal expansion).at n=11A014569
- Expansion of Molien series for automorphism group (2.Weyl(E6)) of E6 lattice.at n=41A014977
- a(n) = 12*a(n-1) + 5*a(n-2) for n >= 2, a(0) = 0, a(1) = 1.at n=4A015610
- Numbers n such that phi(n) | sigma_7(n).at n=47A015765
- Numbers k such that phi(k) | sigma_13(k).at n=40A015771