16723
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19120
- Proper Divisor Sum (Aliquot Sum)
- 2397
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14328
- Möbius Function
- 1
- Radical
- 16723
- 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
- 115
- 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
- a(0)=a(1)=3; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=18A022403
- a(0)=3, a(1)=7; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=17A022406
- Ordered sequence of distinct terms of the form floor(x^i * floor(x^j)), i,j >= 0, where x = sqrt(7).at n=32A022771
- Semiprimes whose digit reversal is a nontrivial power.at n=36A108849
- Semiprimes (A001358) whose digit reversal is a square.at n=31A115710
- Numbers that have 10 terms in their Zeckendorf representation.at n=2A179250
- Number of nX3 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above.at n=4A203970
- Number of nX5 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above.at n=2A203972
- T(n,k)=Number of nXk 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above.at n=23A203975
- T(n,k)=Number of nXk 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above.at n=25A203975
- Triangle of numbers with n 1's and n 0's in their representation in base of Fibonacci numbers (A014417).at n=46A210619
- Number of length n binary words such that maximal runs of 1's are restricted to length one or two and maximal runs of 0's are of odd length.at n=20A236340
- Number of partitions p of n not including round(mean(p)) as a part. (This is "Mathematica round"; for round(x) defined as floor(x + 1/2), see A241734.)at n=40A241339
- Irregular triangle read by rows: T(0, 0) = 2; T(i, j) is the j-th term in the least maximal chain of composites that is longer than the (i-1)-st least maximal chain of composites, where i>0.at n=44A271363
- Number of nX4 0..1 arrays with every element equal to 0, 2, 3, 5 or 6 king-move adjacent elements, with upper left element zero.at n=8A298378
- a(0)=1, a(1)=3, a(2)=7; thereafter a(n) = a(n-1) + a(n-2) + 1.at n=18A355288