839
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 840
- 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
- 838
- Möbius Function
- -1
- Radical
- 839
- 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
- 85
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 146
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- achthundertneununddreißig· ordinal: achthundertneununddreißigste
- English
- eight hundred thirty-nine· ordinal: eight hundred thirty-ninth
- Spanish
- ochocientos treinta y nueve· ordinal: 839º
- French
- huit cent trente-neuf· ordinal: huit cent trente-neufième
- Italian
- ottocentotrentanove· ordinal: 839º
- Latin
- octingenti triginta novem· ordinal: 839.
- Portuguese
- oitocentos e trinta e nove· ordinal: 839º
Appears in sequences
- Number of trees of diameter 5.at n=15A000147
- 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=57A000928
- Cyclic numbers: 10 is a quadratic residue modulo p and class of mantissa is 2.at n=45A001914
- Smallest prime == 7 (mod 8) where Q(sqrt(-p)) has class number 2n+1.at n=16A002146
- Coefficients in expansion of permanent of infinite tridiagonal matrix shown below.at n=43A003113
- Primes p with a Fibonacci primitive root g, i.e., such that g^2 = g + 1 (mod p).at n=43A003147
- Numbers n such that 54*10^n + 1 is prime.at n=7A004203
- Divisible only by primes congruent to 4 mod 5.at n=37A004618
- Divisible only by primes congruent to 6 mod 7.at n=26A004624
- Expansion of g.f.: (1+x^3)*(1+x^4)/((1-x)*(1-x^2)^2*(1-x^4)).at n=26A004657
- Class 4- primes (for definition see A005109).at n=17A005112
- Safe primes p: (p-1)/2 is also prime.at n=21A005385
- Prime self (or Colombian) numbers: primes not expressible as the sum of an integer and its digit sum.at n=18A006378
- Number of connected rooted strength 1 Eulerian graphs with n nodes.at n=7A007126
- Primes for which -10 is a primitive root.at n=56A007348
- Primes of the form 8n+7, that is, primes congruent to -1 mod 8.at n=35A007522
- Primes of form 3*k^2 - 3*k + 23.at n=16A007637
- Generated by a sieve: keep first number, drop every 2nd, keep first, drop every 3rd, keep first, drop every 4th, etc.at n=50A007952
- Coordination sequence T1 for Zeolite Code EUO.at n=18A008095
- a(n) = n^2 - 2.at n=28A008865