865
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1044
- Proper Divisor Sum (Aliquot Sum)
- 179
- 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
- 688
- Möbius Function
- 1
- Radical
- 865
- 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
- 147
- 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
- achthundertfünfundsechzig· ordinal: achthundertfünfundsechzigste
- English
- eight hundred sixty-five· ordinal: eight hundred sixty-fifth
- Spanish
- ochocientos sesenta y cinco· ordinal: 865º
- French
- huit cent soixante-cinq· ordinal: huit cent soixante-cinqième
- Italian
- ottocentosessantacinque· ordinal: 865º
- Latin
- octingenti sexaginta quinque· ordinal: 865.
- Portuguese
- oitocentos e sessenta e cinco· ordinal: 865º
Appears in sequences
- Numbers m such that Fibonacci(m) ends with m.at n=30A000350
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^3)).at n=28A000601
- a(n) is the solution to the postage stamp problem with n denominations and 3 stamps.at n=20A001213
- Primes multiplied by 5.at n=39A001750
- Numbers k such that 39*2^k + 1 is prime.at n=25A002269
- Expansion of 1/(1-2*x^2-3*x^3).at n=12A002447
- Numbers k such that x^k + x + 1 is irreducible over GF(2).at n=20A002475
- Numbers k such that (k^2 + k + 1)/21 is prime.at n=41A002644
- Numbers that are the sum of 11 positive 6th powers.at n=14A003367
- Divisible only by primes congruent to 5 mod 7.at n=38A004623
- Related to representations as sums of Fibonacci numbers.at n=46A006132
- Number of 4-colorings of cyclic group of order n.at n=8A007687
- Coordination sequence T2 for Zeolite Code GOO.at n=20A008112
- Molien series for A_7.at n=25A008630
- E.g.f.: arctanh(tan(x)+sin(x))=2*x+17/3!*x^3+865/5!*x^5+109007/7!*x^7...at n=2A012944
- Expansion of e.g.f.: exp(tanh(x)+sinh(x))=1+2*x+4/2!*x^2+7/3!*x^3+8/4!*x^4+9/5!*x^5...at n=7A013153
- Number of triples (i,j,k) with 1 <= i < j < k <= n and gcd(i,j,k) = 1.at n=18A015616
- Positive integers n such that 2^n == 2^5 (mod n).at n=33A015925
- Expansion of g.f. 1/((1-3*x)*(1-4*x)*(1-6*x)).at n=3A016765
- Pseudoprimes to base 93.at n=13A020221