16766
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 25704
- Proper Divisor Sum (Aliquot Sum)
- 8938
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8200
- Möbius Function
- -1
- Radical
- 16766
- 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
- 159
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 1, -1, 1, 1.at n=24A025258
- Denominators of continued fraction convergents to sqrt(393).at n=13A041747
- Numbers n such that 57*2^n-1 is prime.at n=28A050554
- Number of orbits of the group of units of Z/(n) acting naturally on the 4-subsets of Z/(n).at n=52A063381
- Number of 3-multiantichains of an n-set.at n=6A084870
- Expansion of g.f. Product((1+x^i)/(1-x^i),i=1..n-1)/(1-x^n), with n = 7.at n=27A091778
- a(n) is the smallest positive d such that the n-th prime is the smallest prime p for which p+d is also prime.at n=29A101042
- A101042 sorted. There exists a prime p for which a(n) is the smallest positive d such that p is the smallest prime where p+d is also prime.at n=34A101043
- 5th diagonal of triangle in A059317.at n=23A106113
- Numbers k such that sigma(k) plus the k-th prime is a triangular number.at n=40A115907
- Even numbers k such that if a person is born in year k and lives not more than 100 years, then he never celebrates his prime birthday on a prime year.at n=15A124658
- a(n) = 729*n - 1.at n=22A158395
- Number of permutations of length n which avoid the patterns 4231 and 2143.at n=9A165527
- T(n,k)=number of nXk binary matrices with rows and columns each in strictly increasing order as binary numbers and the number of 1s in rows being even and in columns being odd.at n=85A181009
- 1/4 the number of (n+1) X (n+1) binary arrays with all 2 X 2 subblock sums the same.at n=13A183977
- Number of nondecreasing arrangements of 5 numbers in -(n+3)..(n+3) with sum zero and not more than two numbers equal.at n=16A188238
- Number of free poly-IH5-tiles (holes allowed) with n cells.at n=7A212086
- Number of n X 2 0..3 arrays with no element equal to two plus the sum of elements to its left or two plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.at n=12A240333
- Indices of squares of primes in A098550.at n=33A251240
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 54", based on the 5-celled von Neumann neighborhood.at n=35A270024