2144
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 4284
- Proper Divisor Sum (Aliquot Sum)
- 2140
- 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
- 1056
- Möbius Function
- 0
- Radical
- 134
- Omega Function (Ω)
- 6
- 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
- 32
- 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
- Numbers k such that (k / product of digits of k) is 1 or a prime.at n=23A001103
- a(2n) = a(2n-1) + 2a(2n-2), a(2n+1) = a(2n) + a(2n-1), with a(1) = 2 and a(2) = 3.at n=12A001882
- Numbers that are the sum of 5 positive 5th powers.at n=39A003350
- Numbers that are divisible by the product of their digits.at n=52A007602
- Number of elements w of the Weyl group D(n) such that the roots sent negative by w span an Abelian subalgebra of the Lie algebra.at n=6A007851
- Coordination sequence T2 for Zeolite Code DDR.at n=29A008072
- Coordination sequence T5 for Zeolite Code NON.at n=28A008216
- Coordination sequence T1 for feldspar.at n=31A008254
- Coordination sequence T2 for feldspar.at n=31A008255
- Number of immersions of the oriented circle into the oriented plane with n double points and index n-1.at n=7A008984
- Triangle T(n,k) giving number of immersions of the oriented circle into the oriented plane with n double points and index k, k = -n-1, -n+1, ..., n-1, n+1.at n=37A008985
- Triangle T(n,k) giving number of immersions of the oriented circle into the oriented plane with n double points and index k, k = -n-1, -n+1, ..., n-1, n+1.at n=43A008985
- arctan(log(cos(x)))=-1/2!*x^2-2/4!*x^4+14/6!*x^6+568/8!*x^8...at n=5A012002
- Number of positions in game "Connect Four" (played on usual 6-row, 7-column board) after n moves, up to reflection.at n=5A013582
- a(n) = n*(2*n + 3).at n=32A014106
- Coordination sequence T1 for Zeolite Code CGF.at n=32A019451
- n-th 8k+1 prime plus n-th 8k+7 prime.at n=42A022761
- Number of partitions of n with distinct parts p(i) such that if i != j, then |p(i) - p(j)| >= 3.at n=67A025157
- Numbers that are the sum of 4 nonzero squares in exactly 3 ways.at n=43A025359
- Form a triangle with n numbers in top row; all other numbers are the sum of their parents. E.g.: 4 1 2 7; 5 3 9; 8 12; 20. The numbers must be positive and distinct and the final number is to be minimized. Sequence gives final number.at n=9A028307