16585
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20736
- Proper Divisor Sum (Aliquot Sum)
- 4151
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12720
- Möbius Function
- -1
- Radical
- 16585
- Omega Function (Ω)
- 3
- 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
- 128
- 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
- Triangle read by rows: T(n,k) = number of labeled semigroups of order n with k idempotents.at n=10A058166
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,1,2}.at n=31A080000
- Sum of the squares of the first n nonsquarefree numbers (A013929).at n=18A111732
- Number of base 15 circular n-digit numbers with adjacent digits differing by 3 or less.at n=5A125325
- Number of lines through at least 2 points of a 9 X n grid of points.at n=30A160849
- Number of white square subarrays of (n+1) X (2+1) binary arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with upper left element zero.at n=15A230983
- Number of nX7 binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.at n=3A266427
- T(n,k)=Number of nXk binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.at n=48A266428
- Number of 4 X n binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.at n=6A266430
- G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3*A(x)^2.at n=21A307970
- Number of (2n+1)-digit undulating alternating palindromic primes.at n=9A343677
- The numbers of a square spiral with 1 in the center, lying at integer points of the right branch of the parabola y=n^2.at n=8A357281
- Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,0) = 0^n and T(n,k) = k * Sum_{r=0..n} binomial(3r+k,r) * binomial(r,n-r)/(3*r+k) for k > 0.at n=51A378323
- Consecutive internal states of the linear congruential pseudo-random number generator (281*s + 28411) mod 134456 when started at 1.at n=24A383126