8931
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12880
- Proper Divisor Sum (Aliquot Sum)
- 3949
- 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
- 5472
- Möbius Function
- -1
- Radical
- 8931
- Omega Function (Ω)
- 3
- 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
- 47
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- 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 62.at n=36A031560
- a(n) = (2*n+1)*(12*n+1).at n=19A033576
- 14-gonal (or tetradecagonal) numbers: a(n) = n*(6*n-5).at n=39A051866
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 99 ).at n=32A063372
- Sum_{i for which n - i*(i-1)/2 >= 0} binomial (n - i*(i-1)/2, i).at n=25A063978
- Values of r such that N(r)/r^2 > Pi, where N(r) is the number of integer lattice points (x,y) inside or on a circle of radius r.at n=42A093832
- Odd interprimes divisible by 13.at n=37A124619
- Number of compositions of n which avoid the pattern 112.at n=16A128742
- Centered 47-gonal numbers.at n=19A129428
- a(n)*a(n-13) = a(n-1)*a(n-12)+a(n-6)+a(n-7) with initial terms a(1)=...=a(13)=1.at n=35A133854
- Expansion of -x^2*(19440*x^4+2160*x^3-2304*x^2-150*x+55) /((3*x+1)*(6*x-1)*(6*x+1)*(15*x-1)*(12*x^2-1)).at n=3A138053
- Concatenation of n-th Fibonacci number and n-th prime.at n=10A138821
- Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 4,3 4,4 polyhexes in any orientation on a planar nXnXn triangular grid.at n=6A155310
- a(n) is the smallest positive integer that, when written in binary, contains the binary representations of both the n-th prime and the n-th composite as (possibly overlapping) substrings.at n=48A175349
- Numbers n such that the greatest prime divisor p of n^2+1 has the property that (p - n)^2 + 1 = p.at n=36A206246
- Number of (w,x,y,z) with all terms in {1,...,n} and 3w = x + y + z + n + 1.at n=32A212251
- Number of palindromic partitions of n whose greatest part has multiplicity <= 4.at n=49A238787
- Numbers k such that R_(k+2) + 6*10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=17A256932
- Indices of record values in A266948: least prime p such that p-2 and 6n-p are also prime.at n=11A266950
- a(n) = A277715(n) / 3.at n=46A277716