660
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
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 2016
- Proper Divisor Sum (Aliquot Sum)
- 1356
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 160
- Möbius Function
- 0
- Radical
- 330
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 113
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Names
- German
- sechshundertsechzig· ordinal: sechshundertsechzigste
- English
- six hundred sixty· ordinal: six hundred sixtieth
- Spanish
- seiscientos sesenta· ordinal: 660º
- French
- six cent soixante· ordinal: six cent soixantième
- Italian
- seicentosessanta· ordinal: 660º
- Latin
- sescenti sexaginta· ordinal: 660.
- Portuguese
- seiscentos e sessenta· ordinal: 660º
Appears in sequences
- Orders of noncyclic simple groups (without repetition).at n=4A001034
- A Fielder sequence.at n=11A001640
- Numbers in which every digit contains at least one loop (version 1).at n=20A001743
- Index of (the image of) the modular group Gamma(n) in PSL_2(Z).at n=10A001766
- Triangular numbers plus quarter-squares: n*(n+1)/2 + floor((n+1)^2/4) (i.e., A000217(n) + A002620(n+1)).at n=29A001859
- Highly abundant numbers: numbers k such that sigma(k) > sigma(m) for all m < k.at n=39A002093
- a(n) = n*phi(n).at n=32A002618
- Numbers k such that (k^2 + k + 1)/7 is prime.at n=54A002641
- Beginnings of periodic unitary aliquot sequences.at n=53A003062
- Numbers that are the sum of 6 positive 4th powers.at n=50A003340
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals up to rotation.at n=17A003451
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals rooted at a cell up to rotation and reflection.at n=14A003452
- Discriminants of the known imaginary quadratic fields with 1 class per genus (a finite sequence).at n=46A003644
- Degrees of irreducible representations of alternating group A_11.at n=19A003866
- Degrees of irreducible representations of symmetric group S_11.at n=31A003875
- Degrees of irreducible representations of symmetric group S_11.at n=32A003875
- Representation degeneracies for Ramond strings.at n=13A005303
- a(n) = n*(n+1)*(n+2)*(n+7)/24.at n=9A005582
- a(n) is the smallest positive integer a for which there is an identity of the form a*n*x = Sum_{i=1..m} ai*gi(x)^n where a1, ..., am are in Z and g1(x), ..., gm(x) are in Z[x].at n=11A005729
- From the enumeration of corners.at n=4A006332