540
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 1680
- Proper Divisor Sum (Aliquot Sum)
- 1140
- 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
- 144
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 6
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 43
- 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
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Names
- German
- fünfhundertvierzig· ordinal: fünfhundertvierzigste
- English
- five hundred forty· ordinal: five hundred fortieth
- Spanish
- quinientos cuarenta· ordinal: 540º
- French
- cinq cent quarante· ordinal: cinq cent quarantième
- Italian
- cinquecentoquaranta· ordinal: 540º
- Latin
- quingenti quadraginta· ordinal: 540.
- Portuguese
- quinhentos e quarenta· ordinal: 540º
Appears in sequences
- Number of cusps of principal congruence subgroup Gamma^{hat}(n).at n=36A000114
- Expansion of e.g.f. exp(-x^4/4)/(1-x).at n=6A000138
- Heptagonal numbers (or 7-gonal numbers): n*(5*n-3)/2.at n=15A000566
- Expansion of Product_{k>=1} (1 - x^k)^12.at n=5A000735
- Number of compositions of n into 3 ordered relatively prime parts.at n=34A000741
- Triangle read by rows: T(n,k) = number of permutations of length n with exactly k rising or falling successions, for n >= 1, 0 <= k <= n-1.at n=42A001100
- 10-gonal (or decagonal) numbers: a(n) = n*(4*n-3).at n=12A001107
- a(n) = 3^n - 3*2^n + 3.at n=6A001117
- Numbers that are the sum of 4 cubes in more than 1 way.at n=30A001245
- Triangle of Narayana numbers T(n,k) = C(n-1,k-1)*C(n,k-1)/k with 1 <= k <= n, read by rows. Also called the Catalan triangle.at n=47A001263
- Triangle of Narayana numbers T(n,k) = C(n-1,k-1)*C(n,k-1)/k with 1 <= k <= n, read by rows. Also called the Catalan triangle.at n=52A001263
- Number of ways of making change for n cents using coins of 1, 2, 5, 10, 25, 50 cents.at n=55A001302
- Number of partitions of n into at most 5 parts.at n=28A001401
- Expansion of (Product_{j>=1} (1-(-x)^j) - 1)^9 in powers of x.at n=7A001487
- Highly abundant numbers: numbers k such that sigma(k) > sigma(m) for all m < k.at n=36A002093
- MacMahon's generalized sum of divisors function.at n=14A002127
- Octagonal pyramidal numbers: a(n) = n*(n+1)*(2*n-1)/2.at n=7A002414
- 4-dimensional pyramidal numbers: a(n) = n^2*(n^2-1)/12.at n=9A002415
- Squares written in base 9.at n=20A002442
- Smallest number of stones in Tchoukaillon (or Mancala, or Kalahari) solitaire that make use of n-th hole.at n=40A002491