2691
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
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 4368
- Proper Divisor Sum (Aliquot Sum)
- 1677
- 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
- 1584
- Möbius Function
- 0
- Radical
- 897
- 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
- 115
- 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
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^5)).at n=50A001304
- Coordination sequence T12 for Zeolite Code MFI.at n=33A008164
- Coordination sequence T2 for Zeolite Code MTT.at n=32A008190
- Coordination sequence T4 for Zeolite Code NES.at n=33A008208
- Coordination sequence T1 for Zeolite Code iRON.at n=36A009881
- Numbers k such that Fibonacci(k) == 2 (mod k).at n=42A023174
- a(n) = floor(E_(n+1)/E_(n)) where E_n is n-th Euler number (see A028296 and A000364).at n=39A034971
- Numbers k such that 5*k + 1 is a square.at n=46A036666
- Number of partitions of 5n such that cn(1,5) = cn(4,5) < cn(2,5) = cn(3,5) < cn(0,5).at n=11A036895
- Number of odd nonprimes <= (2n+1)^2.at n=42A038377
- Denominators of continued fraction convergents to sqrt(350).at n=8A041663
- a(n)=(s(n)+3)/8, where s(n)=n-th base 8 palindrome that starts with 5.at n=34A043069
- Numbers n such that string 2,0 occurs in the base 9 representation of n but not of n-1.at n=37A044269
- Numbers k such that the string 6,2 occurs in the base 9 representation of k but not of k-1.at n=36A044307
- Numbers n such that string 9,1 occurs in the base 10 representation of n but not of n-1.at n=28A044423
- Numbers n such that string 2,0 occurs in the base 9 representation of n but not of n+1.at n=37A044650
- Numbers m such that string 9,1 occurs in the base 10 representation of m but not of m+1.at n=28A044804
- a(n) = smallest nonnegative integer not the Nim sum of at most 4 earlier terms.at n=36A054016
- Number of partitions of n in which each part occurs a prime number (or 0) times.at n=55A055923
- Ordered set S defined by these rules: 0 and 1 are in S and if x is a nonzero number in S, then 3x and 9x+2 are in S.at n=50A060141