1856
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 14
- Divisor Sum
- 3810
- Proper Divisor Sum (Aliquot Sum)
- 1954
- 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
- 896
- Möbius Function
- 0
- Radical
- 58
- Omega Function (Ω)
- 7
- 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
- 24
- 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
- Number of partitions into non-integral powers.at n=13A000135
- Number of glycols with n carbon atoms.at n=8A000634
- Solutions of a fifth-order probability difference equation.at n=16A001949
- Worst cases for Pierce expansions (numerators).at n=19A006537
- Shifts left when inverse Moebius transform applied twice.at n=28A007557
- Coordination sequence T6 for Zeolite Code MFS.at n=27A008178
- 2^n*(2^(n+1) - n - 1).at n=5A008353
- Year of birth of n-th President of U.S.A.at n=27A008745
- Coordination sequence for MgNi2, Position Ni2.at n=11A009932
- a(n) = |1^3 - 2^3 + 3^3 - 4^3 + ... + (-1)^(n+1)*n^3|.at n=15A011934
- a(n) = (n+1)*(a(n-1)/n + a(n-2)), with a(0)=1, a(1)=2.at n=7A013989
- Second coordinate of fundamental unit of real quadratic field with discriminant A003658(n), n >= 2.at n=48A014046
- Define the generalized Pisot sequence T(a(0),a(1)) by: a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n). This is T(16,32).at n=7A018923
- Pseudoprimes to base 65.at n=18A020193
- Fibonacci sequence beginning 3, 19.at n=11A022128
- Coordination sequence for root lattice B_4.at n=4A022146
- a(0)=0, a(2*n) = 2*a(n) + 2*a(n-1) + n^2 + n, a(2*n+1) = 4*a(n) + (n+1)^2.at n=36A022560
- Discriminants of quartic fields with 2 complex conjugates (negated).at n=41A023681
- a(n) = least m such that if r and s in {1/2, 1/5, 1/8, ..., 1/(3n-1)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=19A024837
- Coordination sequence T3 for Zeolite Code IFR.at n=30A024984