16686
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 37752
- Proper Divisor Sum (Aliquot Sum)
- 21066
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5508
- Möbius Function
- 0
- Radical
- 618
- Omega Function (Ω)
- 6
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 128
- 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
- a(n) = 4*a(n-1) - a(n-2), a(0)=1, a(1)=6.at n=7A054491
- Combined Diophantine Chebyshev sequences A054491 and A077234.at n=14A077237
- Expansion of (3*x+1)/(1-3*x-3*x^2).at n=7A108306
- Lengths of k-cycles (k > 1) of permutation A114650 in order of their first appearance.at n=17A112664
- Start with 1 and repeatedly reverse the digits and add 55 to get the next term.at n=35A118161
- a(0)=a(1)=1; a(n) = 3*(a(n-1) + a(n-2)).at n=8A134927
- a(n) = (2*n + 1)*(5*n + 6).at n=40A153127
- Number of sequences of n coin flips, that win on the last flip, if the sequence of flips ends with (1,1,0) or (1,0,1).at n=25A196382
- Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=5A317113
- Number of nX6 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=2A317116
- T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=30A317118
- T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=33A317118
- Numbers k such that 429*2^k+1 is prime.at n=40A323115
- Triangle read by rows: T(n,k) is the number of acyclic digraphs on n unlabeled nodes with k arcs and a global source and sink, n >= 1, k = 0..n*(n-1)/2.at n=54A350491
- Number of ways to write n as an ordered sum of nine positive Fibonacci numbers (with a single type of 1).at n=11A357717