816
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 2232
- Proper Divisor Sum (Aliquot Sum)
- 1416
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 256
- Möbius Function
- 0
- Radical
- 102
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 3
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
- yes
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 28
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Names
- German
- achthundertsechzehn· ordinal: achthundertsechzehnste
- English
- eight hundred sixteen· ordinal: eight hundred sixteenth
- Spanish
- ochocientos dieciséis· ordinal: 816º
- French
- huit cent seize· ordinal: huit cent seizième
- Italian
- ottocentosedici· ordinal: 816º
- Latin
- octingenti sedecim· ordinal: 816.
- Portuguese
- oitocentos e dezesseis· ordinal: 816º
Appears in sequences
- Tetrahedral (or triangular pyramidal) numbers: a(n) = C(n+2,3) = n*(n+1)*(n+2)/6.at n=16A000292
- Number of compositions of n into 4 ordered relatively prime parts.at n=15A000742
- Numbers beginning with letter 'e' in English.at n=29A000873
- Padovan sequence (or Padovan numbers): a(n) = a(n-2) + a(n-3) with a(0) = 1, a(1) = a(2) = 0.at n=30A000931
- Numbers k such that (k / product of digits of k) is 1 or a prime.at n=18A001103
- Double-bitters: only even length runs in binary expansion.at n=20A001196
- Number of partitions of n into at most 4 parts.at n=44A001400
- Absolute value of Glaisher's beta'(2n+1).at n=20A002291
- Numbers of the form (p^2 - 49)/120 where p is prime.at n=32A002382
- Sum of the first n even squares: a(n) = 2*n*(n+1)*(2*n+1)/3.at n=8A002492
- Numbers of edges of regular polygons constructible with ruler (or, more precisely, an unmarked straightedge) and compass.at n=52A003401
- Degrees of irreducible representations of Janko group J3.at n=8A003906
- Binomial coefficient C(2n,n-6).at n=3A004312
- Binomial coefficient C(3n, n-3).at n=3A004321
- Binomial coefficient C(6n,n).at n=3A004355
- Expansion of (1-x+x^2)/((1-x)^2*(1-x^2)*(1-x^4)).at n=31A005232
- For n = 0, 1, 2, a(n) = n; thereafter, a(n) = 2*a(n-1) - a(n-2) + a(n-3).at n=13A005314
- a(n) = 6*a(n-1) - a(n-2).at n=4A005319
- a(n) = 1 + Sum_{i=1..n} (n-i+1)*phi(i).at n=19A005598
- a(n) = cost of minimal multiplication-cost addition chain for n.at n=48A005766