11856
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 40
- Divisor Sum
- 34720
- Proper Divisor Sum (Aliquot Sum)
- 22864
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3456
- Möbius Function
- 0
- Radical
- 1482
- Omega Function (Ω)
- 7
- 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
- 50
- 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
- yes
- Odd
- no
Appears in sequences
- Bishops on a 2n+1 X 2n+1 board (see Robinson paper for details).at n=8A005631
- Total number of possible knight moves on an (n+2) X (n+2) chessboard, if the knight is placed anywhere.at n=38A035008
- a(n) = a*b = x*y with (a-b) = (x+y) = A020882(n) (a>b, a>0, b>0, x>0, y>0), gcd(a, b) = gcd(x, y) = 1.at n=41A057229
- Numbers k such that sigma(x) = k has exactly 10 solutions.at n=19A060666
- Rounded total surface area of a regular icosahedron with edge length n.at n=37A071398
- a(n) = lcm(n, A025586(n)), least common multiple of n and largest value in 3x+1 iteration list started at n.at n=38A087259
- a(n) = lcm(4n, A025586(4n)), least common multiple of 4n and the largest value in 3x+1 iteration list started at 4n.at n=38A087261
- Least area of primitive Pythagorean triangle whose legs differ by A058529(n).at n=18A094143
- Area of the Pythagorean triangle a = u^2 - v^2 (cf. A096382) when u=3, v=4,4,5,...at n=12A096383
- Matrix log of triangle A098539, which shifts columns left and up under matrix square; these terms are the result of multiplying each element in row n and column k by (n-k)!.at n=21A111810
- Column 0 of the matrix logarithm (A111810) of triangle A098539, which shifts columns left and up under matrix square; these terms are the result of multiplying the element in row n by n!.at n=6A111811
- One third of the sum of the first n primes, when an integer.at n=36A112270
- Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 4 and repeat; as m = 1,2,3,.. the remaining terms form this sequence.at n=11A112562
- Start with 1 and repeatedly reverse the digits and add 65 to get the next term.at n=37A118163
- Area of primitive Pythagorean triangles sorted on hypotenuse (A020882), then on middle side (or long leg A046087).at n=40A120734
- Define an array by d(m, 0) = 1, d(m, 1) = m; d(m, k) = (m - k + 1) d(m+1, k-1) - (k-1) (m+1) d(m+2, k-2). Sequence gives d(n,3).at n=24A126935
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 1, 1), (1, 0, 1), (1, 1, 0)}.at n=8A150078
- 6 times octagonal numbers: a(n) = 6*n*(3*n-2).at n=26A153796
- Row sums of triangle A173302.at n=29A173303
- Numbers of the form p^4*q*r*s where p, q, r, and s are distinct primes.at n=31A179693