6785
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 8640
- Proper Divisor Sum (Aliquot Sum)
- 1855
- 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
- 5104
- Möbius Function
- -1
- Radical
- 6785
- 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
- 88
- 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) = Fibonacci(n) + n.at n=20A002062
- Number of Twopins positions.at n=45A005686
- Expansion of e.g.f. cos(tan(x)*exp(x)).at n=8A009076
- Expansion of e.g.f.: exp(arctanh(x)+arcsin(x)).at n=7A013170
- Duplicate of A029561.at n=1A028893
- Quasi-Carmichael numbers to base 2: squarefree composites n such that prime p|n ==> p-2|n-2.at n=1A029561
- Numbers with exactly five distinct base-9 digits.at n=19A031986
- a(n) = (2*n+1) * (4*n-1).at n=29A033566
- Number of partitions satisfying cn(0,5) <= cn(1,5) + cn(4,5) + cn(2,5) + cn(3,5).at n=30A039849
- Number of partitions satisfying cn(2,5) <= cn(0,5) + cn(3,5) and cn(2,5) <= cn(0,5) + cn(4,5) and cn(3,5) <= cn(0,5) + cn(1,5) and cn(3,5) <= cn(0,5) + cn(4,5).at n=36A039875
- Number of canonical polygons of n sides.at n=11A052436
- a(n) is the unique positive integer m which has a self-conjugate partition whose parts are the first n primes.at n=32A067773
- Numbers n such that ((n-1)^2+1)/2 and n^2+1 and ((n+1)^2+1)/2 are prime if n is even or (n-1)^2+1 and (n^2+1)/2 and (n+1)^2+1 are prime if n is odd.at n=33A082612
- A000055(n+2)-A023359(n).at n=13A084356
- a(1) = 1, a(2) = 2, a(n) = a(n-1) + d where d is the sum of the absolute differences between all pairs of previous terms.at n=7A089708
- Terms of A094302 without repetition.at n=25A094426
- Numbers n such that sigma(n)=sigma(d_1)*sigma(d_2)*...*sigma(d_k) where d_1 d_2 ... d_k is the decimal expansion of n.at n=17A098771
- Take a <= b such that f(a)+f(b)=concatenation of a and b, where f(k)=k(k+3)/2 (A000096). Sequence gives values of b.at n=29A099149
- Number of subpartitions of partition P=[0,0,0,0,1,1,1,1,1,2,2,2,2,2,2,3,...], where P(n) = [(sqrt(8*n+49) - 7)/2].at n=26A121433
- Number of catacondensed coronoid systems with n hexagons with a single hole.at n=6A122671