657
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 962
- Proper Divisor Sum (Aliquot Sum)
- 305
- 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
- 432
- Möbius Function
- 0
- Radical
- 219
- Omega Function (Ω)
- 3
- 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
- 51
- 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
- no
- Odd
- yes
Names
- German
- sechshundertsiebenundfünfzig· ordinal: sechshundertsiebenundfünfzigste
- English
- six hundred fifty-seven· ordinal: six hundred fifty-seventh
- Spanish
- seiscientos cincuenta y siete· ordinal: 657º
- French
- six cent cinquante-sept· ordinal: six cent cinquante-septième
- Italian
- seicentocinquantasette· ordinal: 657º
- Latin
- sescenti quinquaginta septem· ordinal: 657.
- Portuguese
- seiscentos e cinquenta e sete· ordinal: 657º
Appears in sequences
- Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); A000099 gives values of n where |P(n)| sets a new record; sequence gives A(A000099(n)).at n=11A000323
- Number of 5-dimensional partitions of n.at n=5A000390
- Number of graphical basis partitions of 2n.at n=17A001130
- Number of n-node connected unicyclic graphs.at n=7A001429
- Expansion of (psi(x^2) / psi(-x))^3 in powers of x where psi() is a Ramanujan theta function.at n=8A001937
- a(n) = a(n-1) + a(n-2) - a(n-3).at n=25A002798
- a(0) = 1; for n > 0, a(n) = a(n-1) + floor(sqrt(a(n-1))).at n=54A002984
- a(n) = a(n-1) + a(n-4) with a(0) = 0, a(1) = a(2) = a(3) = 1.at n=23A003269
- Numbers which are the sum of 3 nonzero 4th powers.at n=21A003337
- Divisors of 2^18 - 1.at n=17A003528
- Divisors of 2^36 - 1.at n=48A003543
- a(n) = prime(n) + Fibonacci(n).at n=14A004397
- Divisible only by primes congruent to 3 mod 7.at n=40A004621
- Numbers that are the sum of at most 3 nonzero 4th powers.at n=39A004832
- a(n) = floor(n*phi^8), where phi is the golden ratio, A001622.at n=14A004923
- Number of graphs on n nodes with 3 cliques.at n=10A005289
- Number of Twopins positions.at n=34A005686
- Pseudoprimes to base 10.at n=8A005939
- Number of entries in first n rows of Pascal's triangle not divisible by 3.at n=55A006048
- Numbers k such that phi(k) = phi(sigma(k)).at n=32A006872