3205
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3852
- Proper Divisor Sum (Aliquot Sum)
- 647
- 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
- 2560
- Möbius Function
- 1
- Radical
- 3205
- 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
- 61
- 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
- Coordination sequence T6 for Zeolite Code DFO.at n=43A009880
- Expansion of Product_{m >= 1} (1 + q^m)^(-2).at n=46A022597
- n written in fractional base 7/3.at n=54A024640
- Coordination sequence T1 for Zeolite Code TSC.at n=47A033616
- Number of partitions of n into parts not of form 4k+2, 12k, 12k+5 or 12k-5.at n=48A036019
- Number of 5-ary rooted trees with n nodes and height at most 5.at n=13A036616
- Numbers whose base-7 representation contains exactly three 2's.at n=35A043403
- Numbers k such that the string 5,1 occurs in the base 9 representation of k but not of k-1.at n=43A044297
- Numbers n such that string 0,5 occurs in the base 10 representation of n but not of n-1.at n=34A044337
- Numbers n such that string 0,5 occurs in the base 10 representation of n but not of n+1.at n=34A044718
- Numbers whose base-5 representation contains exactly three 0's and two 1's.at n=19A045171
- Numbers whose base-5 representation contains exactly three 0's and one 3.at n=38A045200
- Dana Scott's sequence: a(n) = (a(n-2) + a(n-1) * a(n-3)) / a(n-4), a(0) = a(1) = a(2) = a(3) = 1.at n=15A048736
- A Diaconis-Mosteller approximation to the Birthday problem function.at n=18A050255
- Number of ordered pairs of integers (x,y) with x^2+y^2 < n^2.at n=32A051132
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 8.at n=22A051973
- The array of A063179 read by diagonals in direction of creation.at n=40A063180
- The array of A063179 read by diagonals in the 'up' direction.at n=40A063181
- Main diagonal of arrays A063180 and A063181.at n=4A063399
- Number of tiling variants for polyominoes with n cells.at n=11A067769