11209
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12240
- Proper Divisor Sum (Aliquot Sum)
- 1031
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10180
- Möbius Function
- 1
- Radical
- 11209
- 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
- 68
- Smith Number
- yes
- 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
- "DIK" (bracelet, indistinct, unlabeled) transform of 1,2,3,4,...at n=12A032287
- a(n)=Sum{T(n,j): j=1,2,...,n}, array T given by A048201.at n=24A048209
- a(n) = (n+1)*(2^(n+1) - n)/2.at n=10A048470
- a(n)=(-1)^n(1 - (1/12)n(n + 1)(12 - n + n^2)).at n=19A080275
- Number of 6-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=11A187511
- Numbers k such that tau(k-1) = (tau(k))^2 = tau(k+1), where tau(k) = A000005(k) (number of divisors of k).at n=39A190266
- Second elementary symmetric function of the first n terms of (2,2,3,3,4,4,5,5...).at n=20A203299
- a(n) is the smallest number k such that n*k is a partition number.at n=46A235704
- Number of partitions of n having population standard deviation >= 2.at n=34A238662
- a(n) = 1 + a(n-1) + a(n-2) + a(n-3) if n>=4; a(1) = a(2) = a(3) = 1.at n=16A248098
- a(n) = (A262026(n) - 1)/2.at n=30A262028
- Length of n-th iterate of the mapping 00->0010, 01->001, 10->011, starting with 00.at n=21A289010
- Numbers k such that 64*10^(2*k) + 8*10^k + 1 is prime.at n=8A309719
- Composite numbers k such that 2^(k-1) == - lambda(k) (mod k), where lambda is the Carmichael lambda function (A002322).at n=4A330446
- a(n) is the number of different ways to partition the set of vertices of a convex n-gon into intersecting polygons.at n=8A352900