12213
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 18720
- Proper Divisor Sum (Aliquot Sum)
- 6507
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7656
- Möbius Function
- 0
- Radical
- 4071
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 156
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Exponential convolution of primes with themselves (divided by 2).at n=8A014346
- Positive numbers having the same set of digits in base 6 and base 10.at n=34A037437
- Denominators of continued fraction convergents to sqrt(533).at n=5A042019
- Denominators of continued fraction convergents to sqrt(548).at n=10A042049
- Numbers k such that 2^k - k is prime.at n=11A048744
- a(n) = Sum_{d|3} phi(d)*n^(3/d).at n=23A054602
- Floor [sqrt{concatenation of first n squares}].at n=5A067124
- Numbers k such that 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)-1 and 6*p(k)*p(k+1)*p(k+2)*p(k+3)*p(k+4)*p(k+5)+1 are twin primes with p(h) = h-th prime.at n=19A129311
- a(n) = 1 if a(n-1) is prime, else a(n) = a(n-2)+a(n-3); starting with a(0) = 0, a(1) = a(2) = 1.at n=45A142884
- 1/12 the number of n X n arrays of squares of integers with every 2 X 2 subblock summing to 29.at n=8A159228
- Magnetic Tower of Hanoi, number of moves of disk number k, generated by a certain algorithm, yielding a "forward moving" non-optimal solution of the [NEUTRAL ; NEUTRAL ; NEUTRAL] pre-colored puzzle.at n=10A183122
- Number of strictly increasing arrangements of 4 nonzero numbers in -(n+2)..(n+2) with sum zero.at n=37A188123
- Numbers k such that 23*k+1 is a square.at n=46A219393
- Expansion of Product_{k>=1} 1/(1 - x^(2*k) - x^(3*k)).at n=32A276519
- Numbers k such that 5*10^k - 43 is prime.at n=21A281513
- Number of partitions of n into 7 distinct and relatively prime parts.at n=46A339672
- Number of grid points covered by a truncated triangle drawn on the hexagonal lattice with the short sides having length n and the long sides length 2*n.at n=43A342914