2907
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 4680
- Proper Divisor Sum (Aliquot Sum)
- 1773
- 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
- 1728
- Möbius Function
- 0
- Radical
- 969
- Omega Function (Ω)
- 4
- 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
- 141
- 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
- no
- Odd
- yes
Appears in sequences
- Number of symmetric, reduced unit interval schemes with n+1 intervals (n>=1).at n=19A005213
- Josephus problem: numbers m such that, when m people are arranged on a circle and numbered 1 through m, the final survivor when we remove every 4th person is one of the first three people.at n=22A005427
- a(n) = n*(5*n+1)/2.at n=34A005475
- a(n) = n*(n+5)*(n+6)*(n+7)/24.at n=12A005587
- Coefficient of x^8 in expansion of (1+x+x^2)^n.at n=5A005716
- Construct triangle in which n-th row is obtained by expanding (1 + x + x^2)^n and take the next-to-central column.at n=8A005717
- Coordination sequence T1 for Zeolite Code LEV.at n=40A008127
- If a, b in sequence, so is ab+5.at n=36A009304
- Coordination sequence T4 for Zeolite Code CON.at n=38A009871
- a(n) = floor( n*(n-1)*(n-2)/22 ).at n=41A011904
- a(n) = floor( n*(n-1)*(n-2)*(n-3)/32 ).at n=19A011942
- a(n) = n*(n+1)*(n+2)/2.at n=17A027480
- Every run of digits of n in base 8 has length 2.at n=38A033006
- Coordination sequence T4 for Zeolite Code SBT.at n=43A033615
- a(1) = 3; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=29A033681
- a(n) = n*(2*n-1)*(2*n+1).at n=9A035328
- Binary packing of Connell sequence (shifted once right).at n=8A036571
- Number of partitions of n such that cn(0,5) = cn(1,5) <= cn(2,5) = cn(3,5) = cn(4,5).at n=64A036871
- Irregular triangle read by rows: T(n,k) = number of orbits of order exactly k under doubling map which remain in a semicircle, with k dividing n.at n=53A038870
- Triangle formed from odd-numbered columns of triangle of expansions of powers of x in terms of Chebyshev polynomials U_n(x). Sometimes called Catalan's triangle.at n=50A039598