811
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 812
- 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
- 810
- Möbius Function
- -1
- Radical
- 811
- 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
- 134
- Smith Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 141
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- achthundertelf· ordinal: achthundertelfste
- English
- eight hundred eleven· ordinal: eight hundred eleventh
- Spanish
- ochocientos once· ordinal: 811º
- French
- huit cent onze· ordinal: huit cent onzième
- Italian
- ottocentoundici· ordinal: 811º
- Latin
- octingenti undecim· ordinal: 811.
- Portuguese
- oitocentos e onze· ordinal: 811º
Appears in sequences
- Number of partitions into non-integral powers.at n=15A000327
- Numbers beginning with letter 'e' in English.at n=24A000873
- Number of primes < prime(n)^2.at n=21A000879
- Primes p of the form 3k+1 such that Sum_{x=1..p} cos(2*Pi*x^3/p) > sqrt(p).at n=34A000921
- Irregular primes: primes p such that at least one of the numerators of the Bernoulli numbers B_2, B_4, ..., B_{p-3} (A000367) is divisible by p.at n=54A000928
- Primes with 3 as smallest primitive root.at n=33A001123
- Primes p such that the multiplicative order of 2 modulo p is (p-1)/3.at n=12A001133
- Number of partitions of n into at most 6 parts.at n=27A001402
- Full reptend primes: primes with primitive root 10.at n=48A001913
- Primes of the form 2^q*3^r*5^s + 1.at n=33A002200
- Primes of the form k^2 - k - 1.at n=17A002327
- A generalized partition function.at n=10A002602
- Number of planar partitions of n decreasing across rows.at n=14A003293
- Even numbers written backwards.at n=59A004093
- Divisible only by primes congruent to 1 mod 5.at n=39A004615
- Divisible only by primes congruent to 6 mod 7.at n=25A004624
- Class 3+ primes (for definition see A005105).at n=47A005107
- a(1)=3, b(n) = Product_{k=1..n} a(k), a(n+1) is the smallest prime factor of b(n)-1.at n=31A005265
- Primes p such that 2p-1 is also prime.at n=29A005382
- Number of Twopins positions.at n=35A005686