9216
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 33
- Divisor Sum
- 26611
- Proper Divisor Sum (Aliquot Sum)
- 17395
- 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
- 3072
- Möbius Function
- 0
- Radical
- 6
- Omega Function (Ω)
- 12
- 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
- yes
- 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
- 29
- 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
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Order of the group SL(2,Z_n).at n=23A000056
- a(n) is smallest number > a(n-1) of form a(i)*a(j), i < j < n.at n=46A000423
- a(n) = binomial(n,2) * 2^(n-1).at n=9A001815
- a(n) = 9*4^n.at n=5A002063
- Cluster series for site percolation problem on square matching lattice (square lattice with 1st and 2nd neighbors connected).at n=7A003201
- Numbers that are the sum of 9 positive 10th powers.at n=9A004809
- a(n) = 9*2^n.at n=10A005010
- Smallest number with exactly n divisors.at n=32A005179
- a(n) = (prime(n) - 1)^2.at n=24A005722
- Number of paraffins.at n=14A006009
- Least number which is side of n Pythagorean triples.at n=46A006593
- The minimal numbers: sequence A005179 arranged in increasing order.at n=37A007416
- Numbers k such that phi(k) divides k.at n=58A007694
- Theta series of {D_9}^{+} packing.at n=25A008436
- Theta series of direct sum of 2 copies of f.c.c. lattice.at n=21A008663
- a(n) = Product_{i=0..6} floor((n+i)/7).at n=26A009641
- Theta series of 16-dimensional 2-modular lattice with min norm 3 and det 256 (the "odd Barnes-Wall lattice").at n=5A014711
- Theta series of shadow of lattice described in A014711.at n=5A014713
- Squares of even octagonal numbers.at n=3A014794
- a(n) = (3*n)^2.at n=32A016766