17768
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 33330
- Proper Divisor Sum (Aliquot Sum)
- 15562
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8880
- Möbius Function
- 0
- Radical
- 4442
- Omega Function (Ω)
- 4
- 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
- 35
- 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
- yes
- Odd
- no
Appears in sequences
- Start with any initial string of n numbers s(1), ..., s(n), with s(1) = 2, other s(i)'s = 2 or 3 (so there are 2^(n-1) starting strings). The rule for extending the string is this as follows: To get s(n+1), write the string s(1)s(2)...s(n) as xy^k for words x and y (where y has positive length) and k is maximized, i.e., k = the maximal number of repeating blocks at the end of the sequence. Then a(n) = number of starting strings for which k = 1.at n=16A093371
- Number of binary sequences of length n with no initial repeats (or, with no final repeats).at n=15A122536
- G.f.: Sum_{n>=0} x^(n*(n+1)/2) / Product_{k=1..n} (1 - k*x^k).at n=25A204856
- Number of binary sequences of length 2n and curling number 1.at n=7A211966
- Number of ways to reciprocally link elements of an n X 5 array either to themselves or to exactly two horizontal and vertical neighbors, without consecutive collinear links.at n=7A220611
- Number of (n+1)X(1+1) 0..2 arrays with the maximum plus the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=4A237772
- Number of (n+1)X(5+1) 0..2 arrays with the maximum plus the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=0A237776
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=10A237779
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=14A237779
- Colombian numbers that are also Bogotá numbers.at n=41A336984
- Number of integer partitions of n such that for some part k the multiplicity of k exceeds k.at n=37A387578