609
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 960
- Proper Divisor Sum (Aliquot Sum)
- 351
- 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
- 336
- Möbius Function
- -1
- Radical
- 609
- 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
- 131
- 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
- no
- Odd
- yes
Names
- German
- sechshundertneun· ordinal: sechshundertneunste
- English
- six hundred nine· ordinal: six hundred ninth
- Spanish
- seiscientos nueve· ordinal: 609º
- French
- six cent neuf· ordinal: six cent neufième
- Italian
- seicentonove· ordinal: 609º
- Latin
- sescenti novem· ordinal: 609.
- Portuguese
- seiscentos e nove· ordinal: 609º
Appears in sequences
- a(n) = Fibonacci(n) - 1.at n=14A000071
- Number of permutations of an n-sequence discordant with three given permutations (see reference) in n-1 places.at n=2A000476
- Strobogrammatic numbers: the same upside down.at n=10A000787
- Numbers beginning with letter 's' in English.at n=33A000870
- Number of primes < prime(n)^2.at n=18A000879
- a(n) = (10n+1)*(10n+9).at n=2A001535
- Tetranacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4), with a(0)=a(1)=0, a(2)=1, a(3)=2.at n=12A001630
- Numbers in which every digit contains at least one loop (version 1).at n=19A001743
- Numbers n such that every digit contains a loop (version 2).at n=54A001744
- Numbers y such that p^2 = x^2 + y^2, 0 < x < y, p = A002144(n).at n=54A002365
- Odd squarefree numbers with an odd number of prime factors that have no prime factors greater than 31.at n=28A002556
- Expansion of 1 / ((1-x)^2*(1-x^2)*(1-x^3)*(1-x^4)).at n=19A002621
- Numbers that are the sum of 4 nonzero 4th powers.at n=28A003338
- Möbius transform of A003965.at n=40A003980
- Number of atoms in a decahedron with n shells.at n=9A004068
- Numbers that are the sum of at most 4 nonzero 4th powers.at n=62A004833
- a(n) = floor(n*phi^7), where phi is the golden ratio, A001622.at n=21A004922
- a(n) = ceiling(n*phi^9), where phi is the golden ratio, A001622.at n=8A004964
- a(n) = 5^n - 2^n.at n=4A005057
- Representation degeneracies for Neveu-Schwarz strings.at n=16A005295