8687
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 6
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10656
- Proper Divisor Sum (Aliquot Sum)
- 1969
- 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
- 6912
- Möbius Function
- -1
- Radical
- 8687
- 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
- 109
- 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
- a(n) = n*(15*n + 1)/2.at n=34A022273
- Pair up the numbers.at n=43A030656
- 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=3A031591
- Numbers with multiplicative persistence value 6.at n=7A046515
- Numbers k such that 5*10^k + R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=10A056713
- Numbers k such that sopf(k) = sopf(k+3), where sopf(k) = A008472(k).at n=15A063969
- Least k such that Sum_{i=1..k} (prime(i) + prime(i+2) - 2*prime(i+1)) = 2n + 1.at n=31A073051
- Pair the odd numbers such that the k-th pair is (r, r+2k) where r is the smallest odd number not included earlier: (1, 3), (5, 9), (7, 13), (11, 19), (15, 25), (17, 29), (21, 35), (23, 39), (27, 45), ... This is the sequence of the product of the members of pairs.at n=22A075320
- a(n)^2 is the square obtained in A075404 (or 0 if no such square exists).at n=31A075405
- a(n) = Sum_{i=1..n} 2^(b(i) - 1), where b(n) is the differences between consecutive primes.at n=32A086769
- Indices of primes in sequence defined by A(0) = 51, A(n) = 10*A(n-1) + 11 for n > 0.at n=17A101573
- a(n) = (2*n - 1) * (2^n - 1).at n=8A118414
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+73)^2 = y^2.at n=9A129289
- Counts 3-wild partitions. In general p-wild partitions of n are defined so that they are in bijection with geometric equivalence classes of degree n algebra extensions of the p-adic field Q_p. Here two algebra extensions are equivalent if they become isomorphic after tensoring with the maximal unramified extension of Q_p.at n=12A131140
- Positive numbers y such that y^2 is of the form x^2+(x+833)^2 with integer x.at n=28A156835
- Products of 3 distinct non-Sophie Germain primes.at n=32A157347
- Number of distinct resistances that can be produced using n equal resistors in, series, parallel and/or bridge configurations.at n=10A174283
- Numbers k that divide 10^(k+1)-1.at n=29A175203
- Irregular triangle of the square root of the sums of squares mentioned in A184763.at n=37A184886
- Numbers k such that sopfr(k + bigomega(k)) = sopfr(k).at n=20A187877