851
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 912
- Proper Divisor Sum (Aliquot Sum)
- 61
- 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
- 792
- Möbius Function
- 1
- Radical
- 851
- 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
- 59
- 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
- no
- Odd
- yes
Names
- German
- achthunderteinundfünfzig· ordinal: achthunderteinundfünfzigste
- English
- eight hundred fifty-one· ordinal: eight hundred fifty-first
- Spanish
- ochocientos cincuenta y uno· ordinal: 851º
- French
- huit cent cinquante et un· ordinal: huit cent cinquante et unième
- Italian
- ottocentocinquantuno· ordinal: 851º
- Latin
- octingenti quinquaginta unus· ordinal: 851.
- Portuguese
- oitocentos e cinquenta e um· ordinal: 851º
Appears in sequences
- Numbers k such that 3^k, 3^(k+1) and 3^(k+2) have the same number of digits.at n=39A001682
- a(n) = a(n-2) + a(n-5).at n=38A001687
- Expansion of 1/((1-x)^3 (1-x^2)^2 (1-x^3) (1-x^4)).at n=11A002626
- Number of integer points in a certain quadrilateral scaled by a factor of n.at n=43A002789
- Number of distinct values taken by 2^2^...^2 (with n 2's and parentheses inserted in all possible ways).at n=11A002845
- Number of strict first-order maximal independent sets in cycle graph.at n=23A007391
- Coordination sequence T2 for Zeolite Code AEI.at n=22A008002
- Coordination sequence T2 for Zeolite Code AFT.at n=22A008027
- Coordination sequence T2 for Zeolite Code AFY.at n=24A008030
- Coordination sequence T1 for Zeolite Code BIK.at n=18A008047
- Composite but smallest prime factor >= 17.at n=20A008367
- Crystal ball sequence for planar net 3.6.3.6.at n=19A008580
- Multiples of 23.at n=37A008605
- Number of distinct orders of permutations of n objects; number of nonisomorphic cyclic subgroups of symmetric group S_n.at n=47A009490
- Coordination sequence T1 for Zeolite Code -WEN.at n=21A009862
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly three 1's.at n=14A013650
- Form a permutation of the positive integers, p_1, p_2, ..., such that the average of each initial segment is an integer, using the greedy algorithm to define p_n; sequence gives p_1 + ... + p_n.at n=36A019445
- Conjectured formula for irreducible 5-fold Euler sums of weight 2n+13.at n=19A019450
- Numbers whose base-6 representation is the juxtaposition of two identical strings.at n=22A020334
- Numbers k such that the continued fraction for sqrt(k) has period 12.at n=44A020351