16705
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 21672
- Proper Divisor Sum (Aliquot Sum)
- 4967
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12288
- Möbius Function
- -1
- Radical
- 16705
- 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
- 128
- 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
- Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers.at n=32A001567
- Euler pseudoprimes: composite numbers n such that 2^((n-1)/2) == +-1 (mod n).at n=19A006970
- Composite numbers k such that k == +-1 (mod 8) and 2^((k-1)/2) == 1 (mod k).at n=14A006971
- Quadruples of different integers from [ 1,n ] with no global factor.at n=26A015622
- Pseudoprimes to base 11.at n=35A020139
- Pseudoprimes to base 17.at n=37A020145
- Odd 10-gonal (or decagonal) numbers.at n=32A028993
- Numbers whose set of base-16 digits is {1,4}.at n=24A032828
- Sums of 4 distinct powers of 4.at n=42A038472
- Numbers whose base-4 representation contains exactly four 0's and four 1's.at n=7A045037
- Euler-Jacobi pseudoprimes: 2^((n-1)/2) == (2 / n) mod n, where (2 / n) is a Jacobi symbol.at n=15A047713
- Family 1 "Rule 90 x Rule 150 Array" read by antidiagonals.at n=30A048710
- 3rd row of Family 1 "90 x 150 array": generations 0 .. n of Rule 90 starting from seed pattern 21.at n=5A048713
- Numbers n such that n | 11^n + 10^n + 9^n + 8^n + 7^n + 6^n + 5^n + 4^n + 3^n + 2^n.at n=24A057288
- Composite numbers k which divide A001045(k-1).at n=26A066488
- Sarrus numbers n (A001567) which satisfy mu(n) = -1 and which are not Super-Poulet numbers (A050217).at n=16A074380
- Least number requiring the base n to produce a prime by base reversal.at n=34A075244
- Sarrus numbers with more than 2 distinct prime factors.at n=17A080747
- Base 10 numbers that are palindromic in bases 2 and 4.at n=46A097856
- Pseudotwinprimes p+2 for primes p such that p+2 divides p^(p+2)+2 and p+2 is composite.at n=9A100873