8691
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 11592
- Proper Divisor Sum (Aliquot Sum)
- 2901
- 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
- 5792
- Möbius Function
- 1
- Radical
- 8691
- Omega Function (Ω)
- 2
- 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
- 52
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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 93.at n=4A031591
- Numbers k such that 261*2^k+1 is prime.at n=50A032507
- Markoff numbers (A002559) multiplied by 3.at n=15A086326
- Start with 1 and repeatedly reverse the digits and add 67 to get the next term.at n=17A118214
- Semiprimes that are not the sum of 3 pentagonal numbers.at n=46A120535
- Semiprimes s such that s-/+2 are primes.at n=39A125215
- a(n) = a(n-1) + s, where s is the least square >= a(n-1) and the first digit of s equals the first digit of a(n-1). a(0)=1.at n=8A175529
- Row sums of triangle A180165.at n=8A180166
- Calendar Problem #27, April 2012 Mathematics Teacher.at n=6A208646
- Smallest number whose home prime (cf. A037274) is the home prime of exactly n natural numbers.at n=14A215408
- Sum of odd quadratic residues of prime(n).at n=53A232505
- Numbers k such that 8*10^k - 49 is prime.at n=28A271269
- a(n) = (a(n-1) * a(n-5) + 1) / a(n-6), a(0) = a(1) = ... = a(5) = 1.at n=28A276529
- a(n) = (9*n^2 - n)/2 + 1.at n=44A276819
- Number of ways to choose an odd partition of each part of an odd partition of 2n+1.at n=11A279374
- Number of ways to choose a partition, with odd parts, of each part of a partition of n into odd parts.at n=23A300301
- a(n) = Sum_{d|n} (-1)^(n/d+1)*d*prime(d).at n=47A318367
- Expansion of Product_{1 <= i < j} (1 + x^(i*j)).at n=46A321286
- G.f. A(x) satisfies A(x) = 1 + x * A(x)^3 * (1 + 2 * A(x)).at n=4A336539
- Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = Sum_{j=0..n} 2^j * binomial(n,j) * binomial(k*n+j+1,n)/(k*n+j+1).at n=32A336574