206
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 312
- Proper Divisor Sum (Aliquot Sum)
- 106
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- yes
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 102
- Möbius Function
- 1
- Radical
- 206
- 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
- 88
- Smith 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
Names
- German
- zweihundertsechs· ordinal: zweihundertsechsste
- English
- two hundred six· ordinal: two hundred sixth
- Spanish
- doscientos seis· ordinal: 206º
- French
- deux cent six· ordinal: deux cent sixième
- Italian
- duecentosei· ordinal: 206º
- Latin
- ducenti sex· ordinal: 206.
- Portuguese
- duzentos e seis· ordinal: 206º
Appears in sequences
- Number of steps to reach 1 in sequence A000546.at n=41A000547
- Number of complemented types of Boolean functions of n variables under action of AG(n,2).at n=4A000614
- Number of switching networks with GL(n,2) acting on the domain and GL(2,2) acting on the range.at n=2A000877
- a(n) = floor(n*log((14/11)*n^(10/9))).at n=45A001195
- Number of partitions of n into at most 4 parts.at n=26A001400
- Number of regular semigroups of order n, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).at n=4A001427
- Winning moves in Fibonacci nim.at n=35A001581
- 2 together with primes multiplied by 2.at n=27A001747
- Number of permutations s of {1,2,...,n} such that |s(i)-i|>1 for each i=1,2,...,n.at n=7A001883
- Hit polynomials.at n=3A001890
- Beatty sequence of (5+sqrt(13))/2.at n=47A001956
- v-pile counts for the 4-Wythoff game with i=2.at n=39A001966
- Numbers m such that 3*2^m - 1 is prime.at n=18A002235
- Numbers k such that 9*2^k + 1 is prime.at n=17A002256
- a(n) = 5*a(n-1) - a(n-2), with a(0) = 1 and a(1) = 2.at n=4A002310
- Numbers m such that m^2 + m + 1 is prime.at n=58A002384
- a(n) = n*a(n-1) + 1, a(0) = 0.at n=5A002627
- Solid partitions of n which are restricted to two planes.at n=7A002835
- Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) = least number > a(n-1) which is a unique sum of two distinct earlier terms.at n=41A002858
- Numbers k such that k and k+1 have same sum of divisors.at n=1A002961