813
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1088
- Proper Divisor Sum (Aliquot Sum)
- 275
- 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
- 540
- Möbius Function
- 1
- Radical
- 813
- 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
- 41
- 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
- achthundertdreizehn· ordinal: achthundertdreizehnste
- English
- eight hundred thirteen· ordinal: eight hundred thirteenth
- Spanish
- ochocientos trece· ordinal: 813º
- French
- huit cent treize· ordinal: huit cent treizième
- Italian
- ottocentotredici· ordinal: 813º
- Latin
- octingenti tredecim· ordinal: 813.
- Portuguese
- oitocentos e treze· ordinal: 813º
Appears in sequences
- Numbers beginning with letter 'e' in English.at n=26A000873
- a(n) = least m such that if a/b < c/d where a,b,c,d are integers in [0,n], then a/b < k/m < c/d for some integer k.at n=33A001000
- Central polygonal numbers: a(n) = n^2 - n + 1.at n=29A002061
- Expansion of x*(1+x^2+x^4)/((1-x)*(1-x^2)*(1-x^3)).at n=57A004652
- a(n) = round(n*phi^7), where phi is the golden ratio, A001622.at n=28A004942
- a(n) = ceiling(n*phi^7), where phi is the golden ratio, A001622.at n=28A004962
- Maxima of the rows of the triangle A259095.at n=28A005577
- x^3 + n*y^3 = 1 is solvable.at n=29A005988
- Horizontally symmetric numbers.at n=54A007284
- Expansion of layer susceptibility series for square lattice.at n=7A007288
- Coordination sequence T1 for Scapolite.at n=18A008262
- Expansion of (1+x^12)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=39A008773
- Expansion of x*(1+x^4)/((1-x)^2*(1-x^4)).at n=57A008811
- Coordination sequence T2 for Zeolite Code ZON.at n=20A009920
- Expansion of 1/(1-x^6-x^7-x^8).at n=54A017848
- Expansion of 1/(1-x^8-x^9-x^10-x^11-x^12-x^13-x^14-x^15-x^16).at n=47A017874
- Powers of cube root of 2 rounded to nearest integer.at n=29A017980
- Powers of cube root of 2 rounded up.at n=29A017981
- (n-2)nd Catalan number is congruent to n/3 mod n.at n=30A019467
- a(n) = a(n-1) + c(n-1) for n >= 2, a( ) increasing, given a(1)=6; where c( ) is complement of a( ).at n=35A022938