9211
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9424
- Proper Divisor Sum (Aliquot Sum)
- 213
- 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
- 9000
- Möbius Function
- 1
- Radical
- 9211
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 122
- 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
- Odd heptagonal numbers (A000566).at n=30A014637
- Pseudoprimes to base 19.at n=40A020147
- Pseudoprimes to base 66.at n=28A020194
- Pseudoprimes to base 75.at n=43A020203
- Strong pseudoprimes to base 16.at n=35A020242
- Strong pseudoprimes to base 46.at n=16A020272
- Strong pseudoprimes to base 66.at n=8A020292
- Strong pseudoprimes to base 75.at n=20A020301
- Strong pseudoprimes to base 76.at n=14A020302
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 23 ones.at n=1A031791
- Numbers k such that 251*2^k+1 is prime.at n=12A032502
- a(n) = (2*n + 1)*(5*n + 1).at n=30A033571
- Number of partitions satisfying cn(0,5) + cn(2,5) + cn(3,5) < cn(1,5) + cn(4,5).at n=35A039881
- Denominators of continued fraction convergents to sqrt(96).at n=8A041173
- Denominators of continued fraction convergents to sqrt(953).at n=10A042845
- Numbers whose base-4 representation contains exactly two 2's and four 3's.at n=33A045147
- E.g.f.: (1/2)/(exp(x) - 1) * (1 - (5 - 4*exp(x))^(1/2)).at n=5A052895
- Trajectory of n under the Reverse and Add! operation carried out in base 4 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.at n=33A075421
- Composite numbers k such that the continued fraction for k/m contains no 2 for any 1 <= m <= k.at n=36A082409
- "The partial sums of the positions where T occurs in this sentence are one, eight, twentyfive, fortynine, eightythree, onehundredtwentysix, ..." (Variation of Aronson's sequence).at n=42A089613