826
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1440
- Proper Divisor Sum (Aliquot Sum)
- 614
- 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
- 348
- Möbius Function
- -1
- Radical
- 826
- Omega Function (Ω)
- 3
- 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
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 90
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Names
- German
- achthundertsechsundzwanzig· ordinal: achthundertsechsundzwanzigste
- English
- eight hundred twenty-six· ordinal: eight hundred twenty-sixth
- Spanish
- ochocientos veintiséis· ordinal: 826º
- French
- huit cent vingt-six· ordinal: huit cent vingt-sixième
- Italian
- ottocentoventisei· ordinal: 826º
- Latin
- octingenti viginti sex· ordinal: 826.
- Portuguese
- oitocentos e vinte e seis· ordinal: 826º
Appears in sequences
- Convolution of A000203 with itself.at n=11A000385
- Numbers beginning with letter 'e' in English.at n=39A000873
- If F(n) is the n-th Fibonacci number, then a(2n) = (F(2n+1) + F(n+2))/2 and a(2n+1) = (F(2n+2) + F(n+1))/2.at n=15A001224
- Generalized Stirling numbers, [n+2,n]_2.at n=7A001701
- Number of non-cyclic hydrocarbons with n carbon atoms (excluding stereoisomers).at n=7A002986
- Numbers that are the sum of 7 positive 5th powers.at n=24A003352
- Erroneous version of A256413.at n=6A004030
- a(n) = (F(2*n-1) + F(n+1))/2 where F(n) is a Fibonacci number.at n=9A005207
- Number of n-node trees not determined by their spectra.at n=13A006610
- Number of irreducible polyhedral graphs with n faces.at n=5A006867
- Coordination sequence T3 for Zeolite Code DDR.at n=18A008073
- Coordination sequence T3 for Zeolite Code MEI.at n=21A008148
- Coordination sequence T4 for Zeolite Code PAU.at n=21A008222
- Coordination sequence T5 for Zeolite Code PAU.at n=21A008223
- Coordination sequence for FeS2-Marcasite, S position.at n=15A009954
- Coefficients in expansion of e as Sum_{n>=1} a(n)/(n*n!*(n+1)!), as found by greedy algorithm.at n=34A011189
- (n-th Lucas number that is not 1) - (n-th number that is 1 or not a Lucas number).at n=12A014244
- Number of triples of different integers from [ 2,n ] with no global factor.at n=18A015618
- Numbers k such that phi(k) + 12 | sigma(k).at n=26A015805
- Numbers k such that phi(k + 10) | sigma(k).at n=42A015830