12665
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
- 16200
- Proper Divisor Sum (Aliquot Sum)
- 3535
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9472
- Möbius Function
- -1
- Radical
- 12665
- 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
- 107
- 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
- Pisot sequences E(5,7), P(5,7).at n=21A020711
- Pisot sequences E(7,10), P(7,10).at n=20A020721
- T(n,n+1), array T as in A047150.at n=8A047156
- Sums of the antidiagonals of the table of k-almost primes (A078840).at n=12A078842
- The values of c in a^2 + b^2 = c^2 where b - a = 23 and gcd(a,b,c) = 1.at n=7A117475
- a(n) = 2*a(n-1) + a(n-2) + n.at n=10A117585
- a(n) = floor(sqrt(a(n-1)^2 + a(n-2)^2 + a(n-1)*a(n-2))), a(1)=1, a(2)=3.at n=24A128424
- Positive numbers y such that y^2 is of the form x^2+(x+23)^2 with integer x.at n=12A156567
- a(n) = 6*a(n-1)-a(n-2) for n > 2; a(1)=17, a(2)=65.at n=4A156570
- Number of torsion pairs in the cluster category of type A_n.at n=6A181517
- Number of 0..n arrays x(0..3) of 4 elements without any interior element greater than both neighbors or less than both neighbors.at n=15A200872
- Principal diagonal of the convolution array A213778.at n=32A213779
- Numbers k such that A084937(3k) > A084937(3k+1).at n=33A249689
- Numbers k such that 7*R_k - 30 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=14A256829
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 237", based on the 5-celled von Neumann neighborhood.at n=25A270982
- Main diagonal of A332365.at n=18A332366
- Sphenic numbers that are also the sum of three consecutive primes.at n=43A335969
- a(n) = A002070(n) + A036689(n).at n=29A366346