5780
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 12894
- Proper Divisor Sum (Aliquot Sum)
- 7114
- 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
- 2176
- Möbius Function
- 0
- Radical
- 170
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 49
- Smith Number
- no
- Vampire 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
Appears in sequences
- a(n) = a(n-1) + a(n-2) - 2, a(0) = 4, a(1) = 3.at n=18A000211
- Number of loopless rooted planar maps with 4 faces and n vertices and no isthmuses.at n=6A006417
- Number of cyclic binary n-bit strings with no alternating substring of length > 2.at n=17A007039
- Number of (marked) cyclic n-bit binary strings containing no runs of length > 2.at n=17A007040
- Coordination sequence T2 for Zeolite Code VET.at n=46A009903
- [ (3rd elementary symmetric function of 3,4,...,n+4)/(3+4+...+n+4) ].at n=15A024191
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 38.at n=31A031536
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 38.at n=3A031716
- a(n) = 5*n^2.at n=34A033429
- Expansion of (1 - x + 3*x^3 - 2*x^4 - 3*x^5)/(1 - 2*x + x^3).at n=18A048162
- When gcd( p(n), q(n) ) increases, where p() is the unrestricted partition function (A000041) and q is the distinct partition function (A000009).at n=12A060745
- Numbers from A066112 that are neither square nor twice a square, i.e., are not in A028982 but are in A028983.at n=22A066134
- a(n) = Lucas(n) + (-1)^n + 1.at n=17A068397
- Squarefree part of n equals bigomega(n).at n=43A069550
- Numbers k such that phi(k) mod core(k) = 1 where core(k) is the squarefree part of k.at n=40A069946
- a(n) = Lucas(4n+2)+2, or 5*Fibonacci(2n+1)^2.at n=4A081067
- a(n) is the smallest number x such that gcd(prime(x)+1,x+1) = n.at n=40A084316
- a(n) = Fibonacci(2*n+1) + Fibonacci(2*n-1) + 2.at n=9A092387
- 2*Jacobsthal(n-1)*Fibonacci(n).at n=9A093045
- Fifth column of (1,5)-Pascal triangle A096940.at n=14A096942