12566
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19344
- Proper Divisor Sum (Aliquot Sum)
- 6778
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6120
- Möbius Function
- -1
- Radical
- 12566
- 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
- 156
- 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
- yes
- Odd
- no
Appears in sequences
- Molien series for alternating group Alt_8 (or A_8).at n=42A008631
- n satisfying sigma(n+1) = sigma(n-1).at n=21A055574
- Numbers k such that sigma(k-1) divides sigma(k+1).at n=25A067130
- Triangle, read by rows, that transforms the (n+m)-dimensional partitions of n into the (n+m+1)-dimensional partitions of n, for fixed m.at n=58A096801
- Column 3 of triangle A096801, which transforms the (n+m)-dimensional partitions of n into the (n+m+1)-dimensional partitions of n, for any fixed m.at n=7A096805
- Number of zig-zag paths from top to bottom of a rectangle of width 11 with n rows whose color is not that of the top right corner.at n=12A153370
- Number of zig-zag paths from top to bottom of a rectangle of width 11 with 2n-1 rows whose color is not that of the top right corner.at n=6A153373
- Number of n X 3 0..2 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other.at n=35A201272
- G.f.: 1/(1-x) = Sum_{n>=0} a(n)*x^n*Product_{k=1..n+1} (1-x^k).at n=27A209405
- Numbers n such that sigma(n+1) - sigma(n-1) = k*n for some integer k, where sigma(n) = A000203 (sum of divisors of n).at n=22A223137
- Numbers k such that sigma(k+1) divides sigma(k-1).at n=22A227304
- Volume of elliptic cone (rounded down) with semi-minor axis = height = n and semi-major axis = 3*n/2.at n=19A228391
- The middle point of row n in binary beanstalk related sequences A179016, A218602, A218616, A233270, A233271.at n=16A233268
- Sphenic numbers (A007304) whose neighbors are sphenic.at n=25A248202
- Numbers k whose nearest neighbors have the same number of divisors, the same number of distinct prime factors, and the same sum of divisors.at n=7A294173
- Row sums of A306234.at n=7A306525
- Record values in A361967.at n=49A361971