12789
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 22230
- Proper Divisor Sum (Aliquot Sum)
- 9441
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7056
- Möbius Function
- 0
- Radical
- 609
- Omega Function (Ω)
- 5
- 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
- 76
- 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
- a(n) = (2*n - 13)*n^2.at n=21A015246
- Numbers k such that k | 5^k + 1.at n=41A015951
- Denominators of continued fraction convergents to sqrt(762).at n=11A042469
- Odd composite numbers divisible by the sum of their prime factors (counted with multiplicity).at n=37A046347
- Ninth column (k=8) of septinomial array A063265.at n=7A063417
- Numerator of 1 - (3/4)^n - frac((3/2)^n), where frac(x) = x - floor(x).at n=7A065622
- Triangle T(n,k) defined by Sum_{1<=k<=n} T(n,k)*u^k*t^n/n! = exp(((1-t)*(1-t^2)*(1-t^3)...)^(-u)-1).at n=26A066045
- a(n) is the area of the triangle with sides prime(n), prime(n+2) and prime(n+4), rounded down to the nearest integer.at n=34A096384
- a(0) = 0, a(1) = 1, a(2) = 1, a(3) = 2, a(4) = 4, for n>3: a(n+1) = SORT[a(n) + a(n-1) + a(n-2) + a(n-3)], where SORT places digits in ascending order and deletes 0's.at n=35A108564
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k UUDD's starting at level 0; here U=(1,1), D=(1,-1) (0<=k<=floor(n/2)).at n=30A114486
- Number of Dyck paths of semilength n having no UUDD's starting at level 0.at n=10A114487
- a(n) = (3/8)*(n-1)*(n-2)*(27*n^2-137*n+180).at n=7A134176
- Numbers k such that phi(k)/k = 16/29.at n=4A172344
- Numbers k such that sigma(tau(k)) equals the sum of distinct primes dividing k.at n=34A173325
- Triangle T(n,m) read by rows, obtained from [A(x)]^m = Sum_{n>=m} T(n,m)*x^n, where A(x) (the g.f. for A069271) satisfies 2*x^2*A(x)^3 = 1 - 2*x*A(x) - sqrt(1-4*x*A(x)).at n=61A188108
- Triangle of numbers C^(6)(n,k) of combinations with repetitions from n different elements over k for each of them not more than 6 appearances allowed.at n=53A213745
- a(n) = 29*n^2.at n=21A244635
- Number of length n+3 0..6 arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.at n=3A249705
- T(n,k)=Number of length n+3 0..k arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.at n=39A249707
- Number of length 4+3 0..n arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.at n=5A249710