16218
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 37908
- Proper Divisor Sum (Aliquot Sum)
- 21690
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4992
- Möbius Function
- 0
- Radical
- 5406
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 159
- 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
- a(n) = a(n-1) + Sum_{0<k<=n/5} a(n-5k) with a(0)=1.at n=34A113444
- Numbers m such that m is k*(the sum of decimal digits squared of m), k=153 case.at n=4A117810
- Numbers k for which digitsum(k) + digitsum(k^2) + digitsum(k^3) = digitsum(k^4).at n=38A118470
- Number of length-n 0..6 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.at n=4A269617
- T(n,k)=Number of length-n 0..k arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.at n=49A269619
- Number of length-5 0..n arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.at n=5A269621
- Numbers k such that (47*10^k + 133)/9 is prime.at n=19A285379
- Sum of values of vertices of type B at level n of the hyperbolic Pascal pyramid.at n=9A292296