689
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 756
- Proper Divisor Sum (Aliquot Sum)
- 67
- 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
- 624
- Möbius Function
- 1
- Radical
- 689
- 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
- 126
- 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
- sechshundertneunundachtzig· ordinal: sechshundertneunundachtzigste
- English
- six hundred eighty-nine· ordinal: six hundred eighty-ninth
- Spanish
- seiscientos ochenta y nueve· ordinal: 689º
- French
- six cent quatre-vingt-neuf· ordinal: six cent quatre-vingt-neufième
- Italian
- seicentoottantanove· ordinal: 689º
- Latin
- sescenti octoginta novem· ordinal: 689.
- Portuguese
- seiscentos e oitenta e nove· ordinal: 689º
Appears in sequences
- Smallest nonnegative number that is the sum of 3 squares in exactly n ways.at n=10A000437
- Smallest number that is the sum of 3 squares in at least n ways.at n=10A000451
- Strobogrammatic numbers: the same upside down.at n=12A000787
- Numbers in which every digit contains at least one loop (version 1).at n=27A001743
- Numbers that are the sum of 5 positive 4th powers.at n=44A003339
- Values of m in the discriminant D = -4*m leading to a new maximum of the L-function of the Dirichlet series L(1) = Sum_{k=1..oo} Kronecker(D,k)/k.at n=12A003420
- Numbers that are the sum of 2 nonzero squares in 2 or more ways.at n=46A007692
- a(n) = n*(4*n+1).at n=13A007742
- Coordination sequence T2 for Zeolite Code MEI.at n=19A008147
- Coordination sequence T2 for Zeolite Code MTT.at n=16A008190
- Expansion of 1/( Product_{j=0..5} (1-x^(2*j+1)) ).at n=44A008675
- Coordination sequence T4 for Zeolite Code -CLO.at n=23A009853
- Coordination sequence T3 for Zeolite Code DFO.at n=20A009877
- a(n) = floor(binomial(n, 2)/2).at n=53A011848
- Numbers k that divide s(k), where s(1)=1, s(j)=13*s(j-1)+j.at n=12A014861
- Numbers k such that phi(k) | sigma(k+4).at n=53A015841
- Numbers k such that sigma(k) = sigma(k+8).at n=8A015876
- Initial pile sizes which guarantee a win for player 2 in a certain variant of Nim.at n=26A016741
- Expansion of 1/(1-x^3-x^4-x^5).at n=28A017818
- Strobogrammatic numbers: numbers that are the same upside down (using calculator-style numerals).at n=30A018846