12761
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14592
- Proper Divisor Sum (Aliquot Sum)
- 1831
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10932
- Möbius Function
- 1
- Radical
- 12761
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- no
- Narcissistic Number
- no
- Collatz Steps
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Sum along upward diagonal of Pascal triangle up to (but not including) center.at n=21A010753
- Numbers k such that the continued fraction for sqrt(k) has period 88.at n=37A020427
- T(n,n-4), array T as in A038738.at n=6A038741
- T(n,n-6), array T as in A038792.at n=15A038796
- Number of positive integers <= 10^n that are divisible by no prime exceeding 5.at n=19A106598
- a(1)=1, a(n)=a(n-1)+n if n even, a(n)=a(n-1)+n^2 if n is odd.at n=40A136047
- Semiprime terms in A136047.at n=11A136048
- a(n) = 343*n - 273.at n=37A157369
- Number of ways of writing n as the sum of 7 triangular numbers.at n=37A226252
- Floor of sums of the non-integer fourth roots of n, as partitioned by the integer roots: floor(Sum_{j=n^4+1..(n+1)^4-1} j^(1/4)).at n=7A248698
- Number of n X 3 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value increasing by 0 or 1 with every step right, diagonally se or down.at n=11A252978
- a(n) = smallest m such that A031131(m) = 2*n.at n=37A261525
- a(n) = F(n+1)*F(n+2) - F(n), where F = A000045 (Fibonacci numbers).at n=9A269803
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1), where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=16A293358
- a(n) is the maximal sum of the elements of A^3 where A is a square matrix of size n whose elements are a permutation of {1, 2, ..., n^2}.at n=2A369396
- Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-x)/(1 + x*exp(x))^2 ).at n=4A379862