7287
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11136
- Proper Divisor Sum (Aliquot Sum)
- 3849
- 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
- 4152
- Möbius Function
- -1
- Radical
- 7287
- Omega Function (Ω)
- 3
- 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
- 163
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Conjectured formula for irreducible 5-fold Euler sums of weight 2n+13.at n=36A019450
- 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 27.at n=40A031525
- Conjecturally, largest attractor in '3x+(2n+1)' problem.at n=52A039515
- Number of partitions satisfying cn(2,5) < cn(0,5) + cn(1,5) + cn(4,5) and cn(3,5) < cn(0,5) + cn(1,5) + cn(4,5).at n=32A039873
- a(n) = 3*a(n-2) + 2*a(n-3) for n > 2, a(0)=1, a(1)=0, a(2)=3.at n=14A053088
- Sum of the first n safe primes.at n=22A066869
- Numbers n such that the trajectory of n under the "3x+1" map reaches n+1.at n=36A070993
- a(n) = (4^(n+1) + 6n + 5)/9.at n=7A073724
- Expansion of (1 - x)^(-1)/(1 + x - 2*x^2).at n=14A077898
- a(0)=1, a(n)=2^n+n-2*a(n-1).at n=15A082383
- a(n) = sum of the first n upper twin primes.at n=28A086168
- Array, A(n, k) = ((n+2)^(k+1) + (k+1)*n*(n+1) - 1)/(n+1)^2, read by antidiagonals.at n=52A094250
- Number of different cycles computed with the generalized 3x+1 problem using C=2, B=Cn+m, A=C^m.at n=17A096010
- Trajectory of 10 under map k -> A111273(k).at n=18A113702
- a(n) = a(n-1) + 3*a(n-2) - a(n-3) - 2*a(n-4), n > 3.at n=14A133993
- One-third of the number of n X n nonnegative integer arrays with every 3 X 3 subblock summing to 1.at n=19A145052
- Triangle read by rows: T(n,0) = 3^n, T(n,k) = T(n,k-1) + T(n-1,k) for 0 < k < n, and T(n,n) = T(n,n-1).at n=31A165992
- Consecutive exclusionary squares: Numbers n such that n^2 does not contain digits of n and (n+1)^2 does not contain digits of n+1.at n=42A247843
- Total sum of number of lambda-parking functions, where lambda ranges over all partitions of n into distinct parts.at n=15A265016
- Harary index of the n X n bishop graph.at n=14A296197