656
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 10
- Divisor Sum
- 1302
- Proper Divisor Sum (Aliquot Sum)
- 646
- 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
- 320
- Möbius Function
- 0
- Radical
- 82
- Omega Function (Ω)
- 5
- 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
- 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
- sechshundertsechsundfünfzig· ordinal: sechshundertsechsundfünfzigste
- English
- six hundred fifty-six· ordinal: six hundred fifty-sixth
- Spanish
- seiscientos cincuenta y seis· ordinal: 656º
- French
- six cent cinquante-six· ordinal: six cent cinquante-sixième
- Italian
- seicentocinquantasei· ordinal: 656º
- Latin
- sescenti quinquaginta sex· ordinal: 656.
- Portuguese
- seiscentos e cinquenta e seis· ordinal: 656º
Appears in sequences
- Expansion of e.g.f. exp(-2*x)/(1-x).at n=7A000023
- Number of ways of making change for n cents using coins of 1, 2, 5, 10, 25 cents.at n=59A001301
- a(1) = 0, a(2) = -2; for n > 2, a(n) + a(n-2) - a(n-3) - a(n-5) - ... - a(n-p) = (-1)^(n+1)*n if n is prime, otherwise = 0, where p = largest prime < n.at n=40A002120
- a(n) = floor(3^n / 2^n).at n=16A002379
- Expansion of (x-1)*(x^2-4*x-1)/(1-2*x)^2.at n=6A003232
- Numbers whose ternary expansion contains no 1's.at n=51A005823
- Number of paraffins (see Losanitsch reference for precise definition).at n=7A006010
- Number of permutations of length n with 1 fixed and 1 reflected point.at n=7A007016
- Number of partitions of n into partition numbers.at n=30A007279
- Palindromic in bases 3 and 10.at n=10A007633
- Coordination sequence T1 for Zeolite Code DAC.at n=16A008067
- Coordination sequence T2 for Zeolite Code DAC.at n=16A008068
- Coordination sequence T2 for Zeolite Code LTN.at n=18A008141
- Coordination sequence T3 for Zeolite Code MFS.at n=16A008175
- Multiples of 16.at n=41A008598
- Molien series of 5 X 5 upper triangular matrices over GF( 2 ).at n=49A008644
- Molien series of 5 X 5 upper triangular matrices over GF( 2 ).at n=48A008644
- Triangle T(n,k), n>=1, read by rows, where T(n,k) is the number of lattice polygons with area n and perimeter 2*k.at n=19A008855
- If a, b in sequence, so is a*b+1.at n=46A009293
- Expansion of tanh(log(1+log(1+x))).at n=6A009770