8189
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8640
- Proper Divisor Sum (Aliquot Sum)
- 451
- 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
- 7740
- Möbius Function
- 1
- Radical
- 8189
- 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
- 158
- 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 period 76.at n=20A020415
- a(n) = (d(n)-r(n))/5, where d = A026057 and r is the periodic sequence with fundamental period (1,0,3,1,0).at n=55A026059
- a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p diving [ A*a(n)+B ] and p=2, A=2.00013, B=3.0.at n=11A029580
- Special connected numbers: minimal and maximal connected numbers (cf. A029827) of a given binary order, i.e., between two consecutive powers of 2.at n=17A036379
- a(n) = 2^n - 3.at n=13A036563
- Sums of 12 distinct powers of 2.at n=11A038463
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 24.at n=34A051965
- Expansion of (1-x)*(1+x)/(1-3*x-x^2+2*x^3).at n=8A052939
- Numbers n such that n | 6^n + 5^n + 4^n + 3^n.at n=12A057248
- New record highs reached in A060030.at n=23A060482
- Numbers k such that k divides the (right) concatenation of all numbers <= k written in base 13 (most significant digit on right, least significant zeros not written).at n=14A061942
- (p^2-5)/4 for odd primes p.at n=40A074367
- a(n) = Sum_{i=0..floor(n/2)} (-1)^(i+floor(n/2))*T(2i+e), where T(n) are tribonacci numbers (A000073) and e = (1/2)(1-(-1)^n).at n=17A075111
- Solve 2^n - 2 = 7(x^2 - x) + (y^2 - y) for (x,y) with x>0, y>0; a(n) = value of y.at n=25A076631
- Sum of numbers in n-th upward diagonal of triangle in A079823.at n=37A079824
- Smallest number having in binary representation a prefix of length n that is also a suffix of its successor.at n=12A091270
- a(n) = smallest k such that the base 4 Reverse and Add! trajectory of A075421(n) joins the trajectory of k.at n=33A091676
- Numbers k such that 2*10^k + 3*R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=16A102951
- a(n+3) = 2a(n+2) - 3a(n+1) + 2a(n); a(0) = 1, a(1) = -1, a(2) = -2.at n=25A105225
- a(n) = 8*n^2 - 3.at n=31A108928