16851
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 23184
- Proper Divisor Sum (Aliquot Sum)
- 6333
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10880
- Möbius Function
- -1
- Radical
- 16851
- Omega Function (Ω)
- 3
- 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
- 203
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- no
- Odd
- yes
Appears in sequences
- Total number of parts in all partitions of n. Also, sum of largest parts of all partitions of n.at n=25A006128
- Numbers k such that 219*2^k+1 is prime.at n=35A032486
- a(n) = 10*n^2+n.at n=40A055437
- a(n) = (10*n+3)*(10*n+17).at n=12A152579
- The number of reachable states in a simple two-player counting game, in which each player starts with the pair (1,1) and one move is to add one of the opponent's numbers to one of your own numbers, but no number can grow above a pre-defined maximum n. The game continues until one of the players has no legal moves left. The winner is the one having the higher sum of his numbers.at n=18A161531
- Denominator of the mean of all parts of all partitions of n.at n=24A236361
- Numbers k such that 8*10^k + 51 is prime.at n=22A287296
- a(n) = 33*2^n - 45 (n>=1).at n=8A304514
- Indices n for which the partial sums of sin(k) (0 <= k <= n) reach a new minimum.at n=30A322288
- a(n) = Sum_{k=1..n} mu(k)*k^3.at n=25A336277
- a(n) = Sum_{k=1..n} mu(k)*k^3.at n=26A336277
- a(n) = Sum_{k=1..n} mu(k)*k^3.at n=27A336277
- Odd composite integers m such that A006190(3*m-J(m,13)) == 3 (mod m), where J(m,13) is the Jacobi symbol.at n=35A340236
- Number of integer partitions of n with origin-to-boundary graph-distance equal to 4.at n=59A384562