2988
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 7644
- Proper Divisor Sum (Aliquot Sum)
- 4656
- 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
- 984
- Möbius Function
- 0
- Radical
- 498
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 48
- 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
- Number of series-reduced trees with n nodes.at n=20A000014
- Number of secondary alcohols (alkanols or alkyl alcohols C_n H_{2n+1} OH) with n carbon atoms.at n=12A000599
- a(n) is the number of integers m which take n steps to reach 1 in '3x+1' problem.at n=36A005186
- Coordination sequence T1 for Zeolite Code BIK.at n=33A008047
- Coordination sequence T4 for Zeolite Code EMT.at n=45A008089
- Coordination sequence T3 for Zeolite Code MFS.at n=34A008175
- Coordination sequence T3 for Zeolite Code RTH.at n=38A009895
- Coordination sequence T2 for Zeolite Code VET.at n=33A009903
- Number of squarefree palindromes over {0, 1, 2} of length 2n+1.at n=27A012212
- Squares on infinite chessboard at n moves from center using a {2,3} fairy knight.at n=45A018839
- a(n)-th nonsquarefree is sum of first k nonsquarefrees for some k.at n=32A020644
- a(n) = C(3n,n) - C(3n,n-4).at n=5A026032
- 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 26.at n=43A031524
- Every run of digits of n in base 3 has length 2.at n=16A033001
- Every run of digits of n in base 11 has length 2.at n=26A033009
- Numbers whose base-11 expansion has no run of digits with length < 2.at n=38A033024
- Cycle of 2 steps possible for 'concatenate a(n) and nextprime(a(n)) is a prime'.at n=24A034592
- Numbers k such that the string 8,0 occurs in the base 9 representation of k but not of k-1.at n=40A044323
- Numbers n such that string 8,8 occurs in the base 10 representation of n but not of n-1.at n=29A044420
- Numbers k such that string 8,8 occurs in the base 10 representation of k but not of k+1.at n=29A044801