16438
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 24660
- Proper Divisor Sum (Aliquot Sum)
- 8222
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8218
- Möbius Function
- 1
- Radical
- 16438
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 190
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- From George Gilbert's marks problem: jumping 4 marks at a time (initial positions).at n=18A019595
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 72 ones.at n=25A031840
- A156977/3.at n=20A164565
- Number of 3-step one space for components leftwards or up, two space for components rightwards or down asymmetric quasi-queen's tours (antidiagonal moves become knight moves) on an n X n board summed over all starting positions.at n=17A187858
- Number of nX3 binary arrays without the pattern 1 1 0 diagonally, vertically or horizontally.at n=5A188517
- Number of nX6 binary arrays without the pattern 1 1 0 diagonally, vertically or horizontally.at n=2A188520
- T(n,k)=Number of nXk binary arrays without the pattern 1 1 0 diagonally, vertically or horizontally.at n=30A188523
- T(n,k)=Number of nXk binary arrays without the pattern 1 1 0 diagonally, vertically or horizontally.at n=33A188523
- Numbers which do not reach zero under either of the iterations: x -> floor(sqrt(x)) * (x - floor(sqrt(x))^2) or y -> ceiling(sqrt(y)) * (ceiling(sqrt(y))^2 - y).at n=16A219963
- Partitions with parts repeated at most twice and repetition only allowed if first part has an even index (first index = 1).at n=55A227135
- Partial sums of the cubes of the tribonacci sequence A000073.at n=7A228609
- a(n) = n*prime(prime(n)) - prime(n)^2.at n=46A230098
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 78", based on the 5-celled von Neumann neighborhood.at n=39A270093
- Numbers m > 3 such that m-1, m, m+1 belong to A307002.at n=47A340748
- a(n) = Sum_{k=1..n} k * sigma_3(k).at n=8A356126