4287
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 5720
- Proper Divisor Sum (Aliquot Sum)
- 1433
- 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
- 2856
- Möbius Function
- 1
- Radical
- 4287
- Omega Function (Ω)
- 2
- 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
- 126
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
Appears in sequences
- a(n) = 3*a(n-1) + a(n-2) with a(0) = 2, a(1) = 3.at n=7A006497
- Coordination sequence T1 for Banalsite.at n=39A008249
- Coordination sequence T1 for Coesite.at n=35A008267
- 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 42.at n=32A031540
- Floor( 7*n^2/2 ).at n=35A032525
- Numerators of continued fraction convergents to sqrt(13).at n=10A041018
- a(n) = Sum_{i=0..2n} (-1)^i * T(i,2n-i), array T as in A049747.at n=48A049749
- Sixth column (r=5) of FS(3) staircase array A062745.at n=9A062749
- Numbers k such that k and 3^k end with the same two digits.at n=42A067749
- Record values in A073524.at n=12A073529
- Number of partitions of 2n for which the square of the largest part equals the sum of the squares of the other parts.at n=30A098101
- k's first occurrence in A102932.at n=42A101255
- Triangle read by rows: T(n,k) is number of Dyck paths of semilength n with height of second peak equal to k (n>=1; 0<=k<=n-1).at n=48A112307
- Numbers n such that n, n-1 and n-2 are semiprimes.at n=44A115393
- Triangle, columns generated from Lucas Polynomials.at n=52A117938
- Numbers k for which 8*k+1, 8*k+5 and 8*k+7 are primes.at n=30A123980
- Numbers m such that binomial(2*m, m) has the same prime factors as binomial(2*k, k) for some k > m.at n=34A129515
- A sequence of asymptotic density zeta(7) - 1, where zeta is the Riemann zeta function.at n=35A143033
- Expansion of x/((1 - x - x^4)*(1 - x)^3).at n=17A145132
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1110-1111 pattern in any orientation.at n=8A146744