9888
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 33
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 26208
- Proper Divisor Sum (Aliquot Sum)
- 16320
- 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
- 3264
- Möbius Function
- 0
- Radical
- 618
- Omega Function (Ω)
- 7
- 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
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- a(1) = 1; thereafter a(n+1) = floor(sqrt(2*a(n)*(a(n)+1))).at n=25A001521
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers), t = (F(2), F(3), ...).at n=13A024589
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (composite numbers), t = (F(2), F(3), F(4), ...).at n=12A025103
- 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 49.at n=27A031547
- Number of partitions in parts not of the form 7k, 7k+2 or 7k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 2 are greater than 1.at n=52A035938
- Numbers having three 8's in base 10.at n=35A043523
- Sum{T(i,n-i): i=0,1,...,n}, array T as in A047040; Sum{T(i,n-i): i=0,1,...,n}, array T given by A047050.at n=15A047041
- a(n) contains n digits (either '8' or '9') and is divisible by 2^n.at n=3A053380
- Number of unlabeled connected graphs with n nodes such that complement is also connected.at n=7A054915
- Maximal number of regions into which 5-space can be divided by n hyperspheres.at n=16A059174
- Numbers n such that sigma(n) is congruent to n mod phi(n).at n=15A066679
- Barriers for bigomega(n): numbers n such that, for all m < n, m + bigomega(m) <= n.at n=45A068597
- Smallest multiple of 8 with digit sum n.at n=33A069536
- Numbers m such that [A070080(m), A070081(m), A070082(m)] is an acute scalene integer triangle with prime side lengths.at n=27A070123
- Sums of members of groups in A076062.at n=26A076060
- Smallest solution to x+n*phi(x) = sigma(x) = x+n*A000010(x) = A000203(x).at n=4A076374
- Number of noncongruent integer-sided tetrahedra with largest side n.at n=12A097125
- a(n) is the number of binary strings of length n such that there exist 4 or more ones in a subsequence of length 5 or less.at n=13A130902
- Number of ways to choose n positive integers less than or equal to 2n such that none of the n integers divides another.at n=33A174094
- Numbers with rounded up arithmetic mean of digits = 9.at n=34A178369