12285
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
- 32
- Divisor Sum
- 26880
- Proper Divisor Sum (Aliquot Sum)
- 14595
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5184
- Möbius Function
- 0
- Radical
- 1365
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
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
- 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
- Smaller of an amicable pair: (a,b) such that sigma(a) = sigma(b) = a+b, a < b.at n=6A002025
- a(n) = (3^n/n!) * Product_{k=0..n-1} (3*k + 4).at n=4A004991
- Odd abundant numbers (odd numbers m whose sum of divisors exceeds 2m).at n=26A005231
- Number of strict 5th-order maximal independent sets in cycle graph.at n=53A007393
- a(n) = dot_product(1,2,...,n)*(6,7,...,n,1,2,3,4,5).at n=29A026046
- Sums of 12 distinct powers of 2.at n=23A038463
- Numerators of continued fraction convergents to sqrt(438).at n=5A041834
- Numerators of continued fraction convergents to sqrt(556).at n=9A042064
- a(n) = 10*n^2+n.at n=34A055437
- a(n) = 9*binomial(n,4) = 3*n*(n-1)*(n-2)*(n-3)/8.at n=15A060008
- New record highs reached in A060030.at n=24A060482
- Numbers expressible as (a^2-1)(b^2-1) in at least 2 distinct ways (b>=a>1).at n=10A063067
- Amicable numbers.at n=12A063990
- Least m such that n = m mod tau(m) if such m exists, otherwise 0.at n=28A066708
- Triangle T(n,k) (n>=1, rows have irregular lengths) giving number of arrangements of k nonattacking princes on an n X n staggered hexagonal torus board.at n=47A067015
- G.f.: (x+2)*(x+1)/((x-1)*(x-2)) = Sum_{n>=0} a(n)*(x/2)^n.at n=12A068156
- Solve 2^n - 2 = 7(x^2 - x) + (y^2 - y) for (x,y) with x>0, y>0; sequence gives value of x.at n=38A076632
- Lexicographically earliest increasing sequence of relatively prime numbers with nondecreasing number of divisors. a(0) = 1, tau(a(n+1)) >= tau(a(n)) and GCD(a(n),a(n+1)) = 1.at n=48A076963
- Expansion of (1-x)^(-1)/(1-x+2*x^2).at n=36A077876
- Expansion of g.f.: (1+3*x^2)/((1-x)*(1+x+2*x^2)*(1-x+2*x^2)).at n=36A107443