11509
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12204
- Proper Divisor Sum (Aliquot Sum)
- 695
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10816
- Möbius Function
- 1
- Radical
- 11509
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 55
- 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
- Numbers n such that sigma(n) - phi(n) = pi(n).at n=4A067788
- Numbers n such that first occurrence of the 10 digits of the i-th root of n contain all the digits from 0 to 9.at n=40A119521
- a(n) = 15*n^2 - 9*n + 1.at n=28A134154
- a(n) = 625*n^2 - 886*n + 314.at n=4A157618
- Number of nX7 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 1 and 1 0 1 vertically.at n=3A207761
- T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 1 and 1 0 1 vertically.at n=48A207762
- Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 1 and 1 0 1 vertically.at n=6A207764
- Fundamental discriminants of real quadratic number fields with class number 10.at n=24A218160
- Number of (7+1) X (n+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.at n=10A250661
- Numbers n such that 3n appears earlier than 2n in A280864.at n=39A280755
- a(n) = n*(n^3 + 2*n^2 - 5*n + 10)/8.at n=17A294259
- Numbers missing from A317416.at n=25A317418
- Numbers k such that the equation x^2 - k*y^4 = -1 has a solution for which |y| > 2.at n=12A356488
- The number of vertices formed when every pair of n points, placed at the vertices of a regular n-gon, are connected by a circle and where the points lie at the ends of the circle's diameter.at n=15A358746
- E.g.f. A(x) satisfies A(x) = exp(-x*A(x)) + x*A(x)^3.at n=6A379876
- Numbers k such that psi(k) = phi(k) + pi(k).at n=3A388650