9988
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 34
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 19152
- Proper Divisor Sum (Aliquot Sum)
- 9164
- 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
- 4520
- Möbius Function
- 0
- Radical
- 4994
- Omega Function (Ω)
- 4
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 91
- 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
- Number of prime knots with n crossings.at n=12A002863
- 'Reverse and Add!' trajectory of 1997.at n=1A063054
- Integers n > 1997 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 1997.at n=27A063055
- Numbers m such that [A070080(m), A070081(m), A070082(m)] is an acute scalene integer triangle with prime side lengths.at n=28A070123
- Numbers n for which there are exactly eight k such that n = k + reverse(k).at n=27A072432
- a(n) = smallest multiple of 4 with sum of digits = n.at n=33A077489
- Length of periodic part of continued fraction expansion of square root of A051451(n), i.e., sqrt(lcm(1..x)) where x is a prime power from A000961.at n=23A077636
- Numbers which are either a divisor or a multiple of their 9's complement.at n=32A084020
- Output of the linear congruential pseudo-random number generator used in function rand() as described in Kernighan and Ritchie, when seeded with 0.at n=2A096554
- G.f. satisfies: A(x) = A( x^2*A000108(x^2) )*x*A000984(x^2), where A000108(x) is the g.f. for the Catalan sequence and A000984(x) = d/dx x*A000108(x).at n=8A096971
- Smallest number not occurring earlier fitting the repeating pattern "99887766554433221100".at n=29A098782
- Berend Jan van der Zwaag's conjectured complete list of numbers that start different "expanding periodic loops" under the mapping described in A053392 and A060630.at n=15A103117
- Composite numbers between largest n-digit prime and the smallest (n+1) digit prime.at n=31A109936
- Generator for the finite sequence A053016.at n=32A136254
- Numbers n such that prime[(n + 1)^2] - prime[n^2] is a perfect square.at n=17A145290
- Coefficients in the expansion of C^3/B^4, in Watson's notation of page 118.at n=10A160527
- Numbers with rounded up arithmetic mean of digits = 9.at n=43A178369
- Number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.at n=21A188250
- Potential magic constants of 8 X 8 magic squares composed of consecutive primes.at n=22A189188
- G.f. satisfies: A(x) = 1 + x/A(-x*A(x)^3).at n=9A213092