9198
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
- 4
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 23088
- Proper Divisor Sum (Aliquot Sum)
- 13890
- 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
- 2592
- Möbius Function
- 0
- Radical
- 3066
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 153
- 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
- sigma_3(n): sum of cubes of divisors of n.at n=19A001158
- Number of ternary squarefree words of length n.at n=25A006156
- a(0) = 1, a(n) = 19*n^2 + 2 for n>0.at n=22A010009
- Numbers k such that k divides 2^(k+1) - 2.at n=31A014741
- Positive integers n such that n | (2^n + n/2 - 1).at n=29A015942
- a(n) = number of integer strings s(0),...,s(n) counted by array T in A026374 that have s(n)=4; also a(n) = T(2n,n-2).at n=5A026377
- Numbers k such that 87*2^k+1 is prime.at n=25A032393
- Sum of n-th powers of divisors of 20.at n=3A034662
- Row 3 of A007754.at n=19A058794
- a(n) = phi(2^n+1)/(2*n).at n=18A069925
- Numbers n such that [A070080(n), A070081(n), A070082(n)] is an isosceles integer triangle with integer area.at n=24A070145
- a(n) = 21a(n-1) - a(n-2), starting with a(0) = 2 and a(1) = 21.at n=3A090729
- a(0)=1, a(n) = sigma_3(2n).at n=10A091986
- a(n) = sigma_3(3n+2).at n=6A092343
- Unique prime factors of 2^n+1 are of the form kn+1. These are the values for k.at n=20A098268
- Triangle, read by rows, of trinomial coefficients arranged so that there are n+1 terms in row n by setting T(n,k) equal to the coefficient of z^k in (1 + 3*z + z^2)^(n-[k/2]), for n>=k>=0, where [k/2] is the integer floor of k/2.at n=50A099512
- Riordan array (1/sqrt(1-6x+5x^2),(1-3x-sqrt(1-6x+5x^2))/(2x)).at n=30A110165
- A000799(n) - A064355(n).at n=56A114699
- a(n) = n^3 - 3*n.at n=21A121670
- Terms of A068563 that are not terms of A124240.at n=38A124241