211
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 4
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 212
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 210
- Möbius Function
- -1
- Radical
- 211
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 39
- Smith Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 47
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- zweihundertelf· ordinal: zweihundertelfste
- English
- two hundred eleven· ordinal: two hundred eleventh
- Spanish
- doscientos once· ordinal: 211º
- French
- deux cent onze· ordinal: deux cent onzième
- Italian
- duecentoundici· ordinal: 211º
- Latin
- ducenti undecim· ordinal: 211.
- Portuguese
- duzentos e onze· ordinal: 211º
Appears in sequences
- Denumerants: Expansion of 1/((1-x)*(1-x^2)*(1-x^5)).at n=61A000115
- Central polygonal numbers (the Lazy Caterer's sequence): n(n+1)/2 + 1; or, maximal number of pieces formed when slicing a pancake with n cuts.at n=20A000124
- Coefficients of a Bessel function (reciprocal of J_0(z)); also pairs of permutations with rise/rise forbidden.at n=4A000275
- Number of binary necklaces of length n with no subsequence 00, excluding the necklace "0".at n=16A000358
- Coefficients of ménage hit polynomials.at n=6A000426
- Primes and squares of primes.at n=52A000430
- Number of steps to reach 1 in sequence A000546.at n=48A000547
- A Beatty sequence: [ n(e+1) ].at n=56A000572
- Number of rooted ternary trees with n nodes; number of n-carbon alkyl radicals C(n)H(2n+1) ignoring stereoisomers.at n=9A000598
- Number of nonnegative solutions to x^2 + y^2 + z^2 <= n.at n=44A000606
- Number of symmetrical planar partitions of n (planar partitions (A000219) that when regarded as 3-D objects have just one symmetry plane).at n=17A000784
- Primes p of the form 3k+1 such that sum_{x=1..p} cos(2*Pi*x^3/p) < -sqrt(p).at n=4A000923
- "First factor" (or relative class number) h- for cyclotomic field Q( exp(2 Pi / prime(n)) ).at n=13A000927
- Lucky numbers.at n=41A000959
- Powers of primes. Alternatively, 1 and the prime powers (p^k, p prime, k >= 1).at n=61A000961
- a(n) = 3^n - 2^n.at n=5A001047
- Numbers m such that Sum_{k=0..m-1} exp(2*Pi*i*k^3/m) != 0.at n=55A001074
- Primes with primitive root 2.at n=22A001122
- a(n) is the solution to the postage stamp problem with 6 denominations and n stamps.at n=4A001211
- a(n) is the solution to the postage stamp problem with n denominations and 5 stamps.at n=5A001215