11661
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 17568
- Proper Divisor Sum (Aliquot Sum)
- 5907
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6864
- Möbius Function
- 0
- Radical
- 897
- Omega Function (Ω)
- 4
- 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
- 37
- 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) = Sum_{k=1..n-1} lcm(k,n-k).at n=46A006580
- Pseudoprimes to base 70.at n=36A020198
- Sequence A001033 gives the numbers n such that the sum of the squares of n consecutive odd numbers x^2 + (x+2)^2 + ... +(x+2n-2)^2 = k^2 for some integer k. For each n, this sequence gives the least value of x.at n=38A056131
- q-factorial numbers 3!_q.at n=22A069778
- Bisection (even part) of Chebyshev sequence with Diophantine property.at n=4A077251
- Combined Diophantine Chebyshev sequences A077249 and A077251.at n=8A077410
- p(p^2-p+1) as p runs through the primes.at n=8A083558
- Number of Pythagorean quadruples mod n; i.e., number of solutions to w^2 + x^2 + y^2 = z^2 mod n.at n=22A096018
- Numbers j such that 24*(j^2) + 25 = k^2.at n=13A106331
- Twin prime products minus 2.at n=9A124659
- Product of successive primes minus 2.at n=27A124669
- a(n) = 9*n^2 - 3.at n=35A157872
- Partial sums of near-repdigit primes A056710.at n=24A172983
- Maximally refined partitions into distinct parts (of any natural number) with n parts.at n=16A179817
- Number of nXnXn triangular 0..4 arrays with each element equal to the product mod 5 of two neighbors.at n=3A193326
- Number of 0..n arrays x(0..3) of 4 elements without any interior element greater than both neighbors.at n=11A200887
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+239)^2 = y^2.at n=7A204765
- Numbers k such that sigma(k - 2) = sigma(k + 2).at n=15A223091
- Let p = prime(n). Smallest j such that q = j*2*p^3-1, r = j*p*2*q^2-1, s = j*p*2*r^2-1, and j*p*2*s^2-1 are prime numbers.at n=4A224612
- Rising diagonal sums of triangle of Fibonacci polynomials (rows displayed as centered text).at n=19A227300