823
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 824
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 822
- Möbius Function
- -1
- Radical
- 823
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 134
- Smith Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 143
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Names
- German
- achthundertdreiundzwanzig· ordinal: achthundertdreiundzwanzigste
- English
- eight hundred twenty-three· ordinal: eight hundred twenty-third
- Spanish
- ochocientos veintitrés· ordinal: 823º
- French
- huit cent vingt-trois· ordinal: huit cent vingt-troisième
- Italian
- ottocentoventitre· ordinal: 823º
- Latin
- octingenti viginti tres· ordinal: 823.
- Portuguese
- oitocentos e vinte e três· ordinal: 823º
Appears in sequences
- Primes that divide at least one term in every Fibonacci sequence.at n=30A000057
- Numbers beginning with letter 'e' in English.at n=36A000873
- Primes p of the form 3k+1 such that Sum_{x=1..p} cos(2*Pi*x^3/p) > sqrt(p).at n=35A000921
- Primes with 3 as smallest primitive root.at n=34A001123
- Full reptend primes: primes with primitive root 10.at n=50A001913
- Divisible only by primes congruent to 4 mod 7.at n=26A004622
- Class 4+ primes (for definition see A005105).at n=10A005108
- Class 3- primes (for definition see A005109).at n=42A005111
- Greater of twin primes.at n=31A006512
- Long period primes: the decimal expansion of 1/p has period p-1.at n=51A006883
- Number of planted trees: all sub-rooted trees from any node are identical; non-root, non-leaf nodes an even distance from the root are of degree 2.at n=53A007439
- Primes of the form 8n+7, that is, primes congruent to -1 mod 8.at n=34A007522
- Prime triples: p; p+2 or p+4; p+6 all prime.at n=25A007529
- Coordination sequence T1 for Zeolite Code APD.at n=19A008034
- Coordination sequence T1 for Zeolite Code AST.at n=21A008036
- Coordination sequence T2 for Zeolite Code MEP.at n=17A008158
- Coordination sequence T3 for Zeolite Code PAU.at n=21A008221
- Coordination sequence T4 for Zeolite Code -CLO.at n=25A009853
- a(n) = ((n+1)-st Lucas number) - (n-th non-Lucas number).at n=12A014243
- Primes p such that multiplicative order of 2 modulo p is odd.at n=39A014663