2199
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
- 4
- Divisor Sum
- 2936
- Proper Divisor Sum (Aliquot Sum)
- 737
- 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
- 1464
- Möbius Function
- 1
- Radical
- 2199
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 32
- Smith Number
- no
- 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
- no
- Odd
- yes
Appears in sequences
- Not integral, withdrawn.at n=7A002692
- a(0) = 1, a(n) = 13*n^2 + 2 for n>0.at n=13A010004
- (n-2)nd Catalan number is congruent to n/3 mod n.at n=48A019467
- Numbers k such that Fibonacci(k) == -2 (mod k).at n=34A023163
- a(n) = position of n^3 + (n+1)^3 + (n+2)^3 in A024975.at n=18A024980
- Expansion of g.f. (1+2*x+3*x^2)/(1-x-x^2-x^3-x^4).at n=11A028831
- Number of noncrossing bushes with n nodes; i.e., rooted noncrossing trees with n nodes and no nonroot nodes of degree 1.at n=7A030981
- 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 30.at n=22A031528
- Numbers whose set of base-12 digits is {1,3}.at n=21A032919
- a(n) = A005248(n) - n.at n=8A033550
- a(n) = (n-1)*(n-2)*(n-3) + n.at n=14A034324
- Composite numbers whose prime factors contain no digits other than 3 and 7.at n=31A036316
- Base 9 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,1.at n=3A037651
- Sums of 3 distinct powers of 3.at n=37A038465
- Numbers k such that string 2,7 occurs in the base 8 representation of k but not of k-1.at n=38A044210
- Numbers k such that string 1,3 occurs in the base 9 representation of k but not of k-1.at n=30A044263
- Numbers n such that string 9,9 occurs in the base 10 representation of n but not of n-1.at n=21A044431
- Numbers n such that string 2,2 occurs in the base 8 representation of n but not of n+1.at n=34A044586
- Numbers n such that string 2,7 occurs in the base 8 representation of n but not of n+1.at n=38A044591
- Numbers k such that string 1,3 occurs in the base 9 representation of k but not of k+1.at n=30A044644