11685
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
- 16
- Divisor Sum
- 20160
- Proper Divisor Sum (Aliquot Sum)
- 8475
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5760
- Möbius Function
- 1
- Radical
- 11685
- Omega Function (Ω)
- 4
- 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
- 81
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n+1)/3.at n=28A048046
- Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n+2)/3.at n=28A048079
- Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n+3)/3.at n=28A048090
- Fifth column (m=4) of (1,6)-Pascal triangle A096956.at n=17A096958
- Primitive elements of A119432.at n=23A119433
- Odd interprimes divisible by 19.at n=35A126231
- Numbers of the form m = p1 * p2 * p3 * p4 where for each d|m we have (d+m/d)/2 prime and p1 < p2 < p3 < p4 each prime.at n=3A128285
- a(n) = n*(7*n-2).at n=41A135703
- JacobiP[n,1,2,5].at n=4A144165
- 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, 0, 0), (0, 1, -1), (1, -1, 1), (1, 1, 0)}.at n=8A149287
- 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, 0), (-1, 1, 0), (0, 1, -1), (1, 0, 1), (1, 1, -1)}.at n=8A149432
- Odd squarefree numbers n such that the cyclotomic polynomial Phi(n,x) has height 5.at n=35A152943
- Numbers whose sum of triangular divisors is also a divisor and greater than 1.at n=16A209311
- Products p*q*r*s of distinct primes for which (p*q*r*s + 1)/2 is prime.at n=24A234501
- Members of a pair (m,k) such that sigma(m) = sigma(k) = sigma(m+k), m < k where sigma = A000203.at n=5A239436
- Members of a pair (m,n) such that sigma(m) = sigma(n) = sigma(n-m), m < n where sigma = A000203.at n=10A239939
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood.at n=26A270288
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 565", based on the 5-celled von Neumann neighborhood.at n=21A272945
- Number of nX4 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=10A300502
- G.f.: Sum_{k>=1} x^(2*k)/(1+x^(2*k)) * Product_{k>=1} 1/(1-x^k).at n=32A305121