520
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 1260
- Proper Divisor Sum (Aliquot Sum)
- 740
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- yes
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 192
- Möbius Function
- 0
- Radical
- 130
- Omega Function (Ω)
- 5
- 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
- 30
- 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
- fünfhundertzwanzig· ordinal: fünfhundertzwanzigste
- English
- five hundred twenty· ordinal: five hundred twentieth
- Spanish
- quinientos veinte· ordinal: 520º
- French
- cinq cent vingt· ordinal: cinq cent vingtième
- Italian
- cinquecentoventi· ordinal: 520º
- Latin
- quingenti viginti· ordinal: 520.
- Portuguese
- quinhentos e vinte· ordinal: 520º
Appears in sequences
- Expansion of e.g.f. exp((-x^3)/3)/(1-x).at n=6A000090
- Numbers that are the sum of 2 squares but not sum of 3 nonzero squares.at n=30A000549
- Number of monosubstituted alkanes C(n-1)H(2n-1)-X with n-1 carbon atoms that are not stereoisomers.at n=14A000621
- Euler's "numerus idoneus" (or "numeri idonei", or idoneal, or suitable, or convenient numbers).at n=59A000926
- Numbers that are the sum of 2 successive primes.at n=54A001043
- a(n) = (4^n + 4^[ n/2 ] )/2.at n=3A001446
- a(n) = a(n-1) + a(n-2) + 1, with a(0) = 0 and a(1) = 2.at n=12A001610
- Numbers y such that p^2 = x^2 + y^2, 0 < x < y, p = A002144(n).at n=48A002365
- Number of equivalence classes of binary sequences of primitive period n.at n=16A002730
- The square sieve.at n=39A002960
- Number of hexagonal n-element polyominoes whose graph is a path.at n=8A003104
- Schur's 1926 partition theorem: number of partitions of n into parts 6n+1 or 6n-1.at n=52A003105
- Numbers that are the sum of 2 positive cubes.at n=27A003325
- Numbers that are the sum of 5 positive 5th powers.at n=12A003350
- Numbers that are the sum of 12 positive 7th powers.at n=4A003379
- Sum of 10 nonzero 8th powers.at n=2A003388
- Numbers that are the sum of 9 positive 9th powers.at n=1A003398
- Discriminants of the known imaginary quadratic fields with 1 class per genus (a finite sequence).at n=41A003644
- Sum of remainders of n mod k, for k = 1, 2, 3, ..., n.at n=55A004125
- a(n) = floor(100*log_2(n)).at n=36A004262