9928
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 19980
- Proper Divisor Sum (Aliquot Sum)
- 10052
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 4608
- Möbius Function
- 0
- Radical
- 2482
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 42
- 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 ordered triples of integers from [ 2,n ] with no global factor.at n=40A015633
- 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=30A031547
- Numbers n such that phi(reversal(n)) = reversal(phi(n)). Ignore leading 0's.at n=16A069282
- Numbers k such that the k-th prime is of the form 2*j^2 + 1.at n=33A090612
- Expansion of 1 / ((1 - 4*x) * sqrt(1 + 4*x)) in powers of x.at n=7A091520
- a(n) is the largest number such that all of a(n)'s length-n substrings are distinct and divisible by 73.at n=3A093273
- Euler-Seidel matrix T(k,n) with start sequence e.g.f. 2x/(1+e^(2x)), read by antidiagonals.at n=49A099028
- Numbers which are the sum of two positive cubes and divisible by 17.at n=9A099178
- a(0) = a(1) = 1; for n >= 2, a(n) = a(n-1) + a(n-2) - n if that number is positive and not already in the sequence, otherwise a(n) = a(n-1) + a(n-2) + n.at n=21A117821
- Number of (directed) Hamiltonian paths in the n-Möbius ladder graph.at n=14A137883
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, 0), (-1, 1, 1), (0, 0, -1), (1, 0, 0)}.at n=9A148641
- a(n) = n^3 + (n+2)^3.at n=16A153976
- Numbers k such that k / (A000005(k)*(A000005(k)+1)/2) is an integer.at n=40A160921
- a(n) = (prime(n))^2 - (nonprime(n))^2.at n=27A161757
- G.f. -x*(x-1)*(1+x)/(1-x-8*x^2-x^3+x^4).at n=9A171065
- Partial sums of Pillai primes (A063980).at n=37A172034
- Numbers k such that 9k+4 are terms in A072841.at n=25A175518
- Eight white queens and one red queen on a 3 X 3 chessboard. G.f.: (1 - 3*x)/(1 - 5*x - 2*x^2).at n=6A180038
- Number of 5-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=15A187510
- Number of (n+1)X(n+1) 0..1 arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal.at n=4A187668