8005
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9612
- Proper Divisor Sum (Aliquot Sum)
- 1607
- 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
- 6400
- Möbius Function
- 1
- Radical
- 8005
- 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
- yes
- 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
- Number of partitions into non-integral powers.at n=36A000148
- Numerators of worst case for Engel expansion.at n=35A006539
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MOR = Mordenite Na8[Al8Si40O96].24H2O starting with a T2 atom.at n=12A019180
- Numbers k such that the continued fraction for sqrt(k) has period 15.at n=37A020354
- Number of partitions of n such that cn(1,5) <= cn(0,5) = cn(2,5) < cn(3,5) = cn(4,5).at n=75A036852
- Digit sum of 'odd' number equals digit sum of 'sum' and 'juxtaposition' of its prime factors (counted with multiplicity).at n=39A036927
- Numerators of continued fraction convergents to sqrt(163).at n=8A041300
- Numbers whose base-6 representation has exactly 6 runs.at n=6A043614
- Number of colors that can be mixed with up to n units of yellow, blue, red.at n=37A048134
- Squarefree n such that the elliptic curve n*y^2 = x^3 - x arising in the "congruent number" problem has rank 3.at n=11A062693
- Average of terms of n-th row of A077321.at n=32A077325
- a(n) = n^3 + 5.at n=20A084381
- Number of prime pairs below 10^n having a difference of 12.at n=5A093741
- Start with 1 and repeatedly reverse the digits and add 24 to get the next term.at n=41A118610
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1010-1111-0010 pattern in any orientation.at n=10A146629
- Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1010-1111-0010 pattern in any orientation.at n=22A146631
- Number of binary strings of length n with no substrings equal to 0000 or 0011.at n=15A164388
- a(n) = 15n^2 + 3n + 1.at n=22A165806
- Cubes (n * n * n) in carryless arithmetic mod 10.at n=25A169885
- Triangular array: the fusion of (p(n,x)) by (q(n,x)), where p(n,x)=sum{F(k+1)*x^(n-k) : 0<=k<=n}, where F=A000045 (Fibonacci numbers), and q(n,x)=(x+1)^n.at n=58A193919