9524
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 16674
- Proper Divisor Sum (Aliquot Sum)
- 7150
- 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
- 4760
- Möbius Function
- 0
- Radical
- 4762
- Omega Function (Ω)
- 3
- 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
- 78
- 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(0) = 1, a(n) = 18*n^2 + 2 for n>0.at n=23A010008
- Number of partitions of n into an odd number of parts, the least being 4; also, a(n+4) = number of partitions of n into an even number of parts, each >=4.at n=67A027190
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 54 ones.at n=29A031822
- a(n) = floor(47*(n-3/2)^(3/2)).at n=34A050256
- Number of partitions of n such that the least part occurs with even multiplicity.at n=36A096374
- a(n) = 8*n^2 + 8*n + 4.at n=34A108099
- Total sum of parts of multiplicity 2 in all partitions of n.at n=28A117525
- a(n) = Sum_{k=0..[n/2]} 2^(n-2*k-1)*C(n-1,2*k)*C(2*k,k)/(k+1)*a(k), with a(0)=1.at n=9A118929
- Sum of previous term and preceding relatively prime terms.at n=18A119746
- Number of n X n binary arrays, symmetric under 90-degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.at n=8A144058
- Partial sums of ceiling(n^2/4).at n=48A175287
- Numbers n such that there is no square n-gonal number greater than 1.at n=17A188896
- Number of rhombuses on a (n+1)X9 grid.at n=29A190097
- Successive values of variable in iterative system. See formula.at n=3A196197
- Moments of the quadratic coefficient of the characteristic polynomial of a random matrix in SU(2) X SU(2) (inside USp(4)).at n=8A202856
- Expansion of g.f. 1/ (1-x^1*(1-x^(m+1))/ (1-x^2*(1-x^(m+2))/ (1- ... ))) for m=6.at n=19A228646
- Number of circular permutations i_0, i_1, ..., i_n of 0, 1, ..., n such that all the n+1 numbers i_0^2+i_1, i_1^2+i_2, ..., i_{n-1}^2+i_n, i_n^2+i_0 are of the form (p-1)/2 with p an odd prime.at n=14A229082
- Least even k such that sfdf(k-3) > sfdf(k-1) >= A050376(n), where sfdf(n) is the smallest Fermi-Dirac factor of n (A223490).at n=28A244343
- Least number k such that k^n - k +/- 1 are twin primes, or 0 if no such k exists.at n=41A248082
- Number of length 1+3 0..n arrays with every four consecutive terms having the sum of some three elements equal to three times the fourth.at n=18A248538