16508
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 28896
- Proper Divisor Sum (Aliquot Sum)
- 12388
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8252
- Möbius Function
- 0
- Radical
- 8254
- Omega Function (Ω)
- 3
- 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
- 172
- 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
- (prime(n)*(prime(n+1)-1) + (prime(n)-1)*prime(n+1)) / 2.at n=29A099909
- Number of distinct ribbon Schur functions with n boxes; also the number of distinct multisets of partitions determined by all coarsenings of compositions of n.at n=15A120421
- Triangle read by rows: T(n,k) = is the number of directed column-convex polyominoes of area n having along the lower contour exactly k reentrant corners, i.e., a vertical step that is followed by a horizontal step (n >= 1, k >= 0).at n=45A121466
- Riordan array (1/(1-2x), x/((1-x)(1-2x))).at n=48A124237
- Partial sums of A243980.at n=23A244050
- Number of nX4 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s.at n=4A297633
- T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s.at n=32A297637
- Number of 5Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s.at n=3A297641
- Iterate function composition by applying y=abs(x) or y=x-1. a(n) is the number of functions at distance n from the identity (y=x) in the graph of all possible results.at n=22A334738
- For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = n^4*s, where s is the population variance of the values of |v|.at n=10A345690