989
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1056
- 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
- 924
- Möbius Function
- 1
- Radical
- 989
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 49
- 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
- neunhundertneunundachtzig· ordinal: neunhundertneunundachtzigste
- English
- nine hundred eighty-nine· ordinal: nine hundred eighty-ninth
- Spanish
- novecientos ochenta y nueve· ordinal: 989º
- French
- neuf cent quatre-vingt-neuf· ordinal: neuf cent quatre-vingt-neufième
- Italian
- novecentoottantanove· ordinal: 989º
- Latin
- nongenti octoginta novem· ordinal: 989.
- Portuguese
- novecentos e oitenta e nove· ordinal: 989º
Appears in sequences
- a(n) = n*(n+3)/2.at n=43A000096
- a(1)=0; for n>1, a(n) = number of isomeric hydrocarbons of the acetylene series with carbon content n.at n=11A000642
- a(0) = 1, a(1) = 5, a(n) = 4*a(n-1) - a(n-2).at n=5A001834
- Numerators of Cotesian numbers (not in lowest terms): A002176(n)*C(n,0).at n=7A002177
- a(2*n) = a(2*n-1) + a(2*n-2), a(2*n+1) = 2*a(2*n) + a(2*n-1); a(0) = a(1) = 1.at n=11A002531
- Numbers that are the sum of 9 positive 6th powers.at n=14A003365
- Add 4, then reverse digits; start with 0.at n=38A003608
- a(n) = ceiling(n*phi^9), where phi is the golden ratio, A001622.at n=13A004964
- Number of strict 7th-order maximal independent sets in cycle graph.at n=45A007394
- Generated by a sieve: keep first number, drop every 2nd, keep first, drop every 3rd, keep first, drop every 4th, etc.at n=54A007952
- Coordination sequence T1 for Zeolite Code KFI.at n=24A008123
- Coordination sequence T1 for Zeolite Code MER.at n=23A008160
- Composite but smallest prime factor >= 17.at n=26A008367
- Multiples of 23.at n=43A008605
- Expansion of (1+x)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=37A008762
- Coordination sequence T3 for Zeolite Code ZON.at n=22A009921
- f-vectors for simplicial complexes of dimension at most 1 (graphs) on at most n-1 vertices.at n=18A011826
- a(n) = n*(2*n-3).at n=23A014107
- a(n) = n^2 + 3*n - 1.at n=30A014209
- a(n) = prime(n)*(prime(n+1)-1)/2.at n=13A014303