16658
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 24990
- Proper Divisor Sum (Aliquot Sum)
- 8332
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8328
- Möbius Function
- 1
- Radical
- 16658
- 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
- 190
- Smith Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, s(1) = 1, s(n) = 2, |s(i) - s(i-1)| <= 1 for i >= 2, |s(2) - s(1)| = 1, |s(3) - s(2)| = 1 if s(2) = 1. Also T(n,n-2), where T is the array in A026268.at n=10A026288
- Number of ternary words of length n (beginning 0) with autocorrelation function 2^(n-1)+1.at n=10A045695
- Number of asymmetric trees with a forbidden limb of length 3.at n=24A052326
- Number of 2-trees rooted at a triangle.at n=8A063688
- Vinogradov's constants arising in enumeration of solutions to Waring's problem in the evil numbers (A001969).at n=28A206375
- a(n) = 2*a(n-1) + a(n-2) + n^2 for n > 1, with a(0) = 0, a(1) = 1.at n=10A271389
- Take a squarefree semiprime and take the difference of its prime factors. If it is a squarefree semiprime repeat the process. Sequence lists the squarefree semiprimes that generate other squarefree semiprimes only in the first k steps of this process. Case k = 4.at n=33A296811
- Take a squarefree semiprime and take the difference of its prime factors. If it is a squarefree semiprime repeat the process. Sequence lists the squarefree semiprimes that generate other squarefree semiprimes only in the first k steps of this process. Case k = 5.at n=8A296812
- Number of nX7 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.at n=3A297223
- T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.at n=48A297224
- Number of 4Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.at n=6A297226
- Number of compositions (ordered partitions) of n into prime parts that do not divide n.at n=39A300703
- Sum of binomial(Y(2,p), 2) over the partitions p of n, where Y(2,p) is the number of part sizes with multiplicity 2 or greater in p.at n=28A304825
- Number of n X n 0..1 arrays with every element unequal to 1, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=3A305686
- Number of nX4 0..1 arrays with every element unequal to 1, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=3A305688
- T(n,k)=Number of nXk 0..1 arrays with every element unequal to 1, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.at n=24A305692
- Number of 4-element subsets of [n] whose sum is a triangular number.at n=46A320850
- First position of n in A354578, where A354578(k) is the number of integer compositions whose run-sums constitute the k-th composition in standard order (graded reverse-lexicographic, A066099).at n=27A354905
- Triangle read by rows: T(n,k) is the number of k-trees with n unlabeled nodes rooted at a hedron.at n=68A370772