12195
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 21216
- Proper Divisor Sum (Aliquot Sum)
- 9021
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6480
- Möbius Function
- 0
- Radical
- 4065
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 37
- 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
- Numbers k such that 6!*(2*k-7)!/(k!*(k-1)!) is an integer.at n=12A004786
- Numbers k such that 7!*(2k-8)!/(k!*(k-1)!) is an integer.at n=14A004787
- a(n) = ceiling((n^3)/2).at n=29A036486
- Second pentagonal numbers with even index: a(n) = n*(6*n+1).at n=45A049453
- Thickened cube numbers: a(n) = n*(n^2 + (n-1)^2) + (n-1)*2*n*(n-1).at n=14A050492
- Numbers n such that 229*2^n-1 is prime.at n=33A050866
- 4th level triangle related to Eulerian numbers and binomial transforms (A062254 is third level, A062253 is second level, triangle of Eulerian numbers is first level and triangle with Z(0,0)=1 and Z(n,k)=0 otherwise is 0th level).at n=25A062255
- G.f.: (1 + Sum_{ i >= 0 } 2^i*x^(2^(i+1)-1)) / (1-x)^3.at n=44A063916
- Row sums of triangle A091492.at n=45A091493
- Take pairs (a, b), sorted on a, such that T(a)+T(b)=concatenation of a and b, where T(k) is the k-th triangular number A000217(k). Sequence gives values of a.at n=22A096031
- A Catalan-related transform of 3^n.at n=8A102898
- Least k such that prime(n)^3 divides binomial(2k,k).at n=9A110496
- Numbers k such that 2*k+1, 4*k+1, 8*k+1 and 16*k+1 are primes.at n=14A124412
- a(n) = n*(n+1)*(n^4 + 2*n^3 - 2*n^2 - 3*n + 3)/2.at n=5A152725
- a(n) = 729*n - 198.at n=16A156772
- Coefficients in the expansion of C^6 / B^7, in Watson's notation of page 106.at n=7A160460
- a(n) = ((2*n+1)^3+(-1)^n)/2.at n=14A175109
- Alternating sums of powers for 1,2,3,4 and 5.at n=6A198628
- Number of (w,x,y,z) with all terms in {0,...,n} and 2w=floor((x+y+z)/2).at n=28A212747
- Primitive numbers in A229305.at n=43A229309