13212
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 33488
- Proper Divisor Sum (Aliquot Sum)
- 20276
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4392
- Möbius Function
- 0
- Radical
- 2202
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 3
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 76
- 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
- McKay-Thompson series of class 39A for Monster.at n=47A058659
- Numbers k such that k+1 is composite and divides 3^k-2^k.at n=26A068410
- Numbers divisible by the sum of factorials of their digits [A061602(n)] and also terminate in the sum of factorials of their digits.at n=15A071064
- (n / product of digits of n) is a semiprime.at n=32A085773
- Numbers that are multiples of their digital product, where this digital product also appears as their least significant digits.at n=26A167620
- a(n) = [x^n] G_{n+1}(x) where G_n(x) = F(x*G_n(x)^n) and F(x) = g.f. of A185072 such that [x^n] G_n(x) = 0.at n=6A185082
- Number of partitions of n having depth 2; see Comments.at n=40A237750
- Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 8.at n=45A240017
- Number of (3+1) X (n+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically.at n=16A258556
- Total number of corners in all partitions of n. A corner of a partition is a point of degree two in the corresponding Ferrers diagram.at n=24A265258
- Number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 259", based on the 5-celled von Neumann neighborhood.at n=57A271054
- Triangle read by rows: T(n,k) is the number of multisets of k ternary words with a total of n letters.at n=31A275414
- Growth series for group with presentation < S, T : S^2 = T^3 = (S*T)^9 = 1 >.at n=28A298811
- a(n) = n * Sum_{d|n} binomial(d+2,3)/d.at n=35A343544
- Zuckerman numbers which when divided by the product of their digits, give a quotient which is a Niven (Harshad) number.at n=33A343682
- For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = sum of the values of |v|.at n=51A345433
- Irregular triangle read by rows: T(n,k) (0 <= k <= n^2) are coefficients of cluster density function for site percolation on an n X n 2D square lattice with open boundary conditions.at n=22A365946
- Triangle read by rows T(n, k) is the number of permutations on n elements whose square has k descents, for n >= 1 and 0 <= k <= n-1.at n=32A373691
- Number of states in minimal deterministic finite automaton recognizing the language of binary strings that contain, as contiguous blocks, all binary strings of length n.at n=3A375919
- a(n) is the number of isosceles trapezoids in a triangular grid of side length n.at n=15A389363