16945
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20340
- Proper Divisor Sum (Aliquot Sum)
- 3395
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13552
- Möbius Function
- 1
- Radical
- 16945
- 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
- 58
- Smith Number
- no
- 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
- no
- Odd
- yes
Appears in sequences
- Erroneous version of A309982.at n=16A006775
- Quadruples of different integers from [ 1,n ] with no common factors between triples.at n=29A015625
- Quadruples of different integers from [ 2,n ] with no common factors between triples.at n=29A015629
- Number of squares on infinite chessboard at <= n knight's moves from a fixed square.at n=35A018836
- Numbers k such that the continued fraction for sqrt(k) has period 51.at n=28A020390
- Sizes of successive balls in D_4 lattice.at n=41A046949
- G.f. = continued fraction: A(x)=1/(1-x/(1-2*x^2/(1-3*x^3/(1-4*x^4/(...))))).at n=14A088357
- Expansion of x*(403+2967*x+1047*x^2-x^3)/(1-x)^4.at n=2A165808
- First column of triangle in A176452.at n=17A176485
- Number of ways to place 5 nonattacking semi-queens on an n X n board.at n=6A202656
- Number of (n+2)X(7+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=5A254906
- Number of (6+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=6A254912
- Numbers k such that 389*2^k+1 is prime.at n=9A323039