16639
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
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19024
- Proper Divisor Sum (Aliquot Sum)
- 2385
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14256
- Möbius Function
- 1
- Radical
- 16639
- 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
- 89
- 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
- Denominators of continued fraction convergents to sqrt(609).at n=10A042169
- Numbers whose base-4 representation contains exactly three 0's and four 3's.at n=20A045080
- Positions of the elements of the quasicyclic group Z+(2a+1)/(2^b) [a > 0 and a < 2^(b-1), b > 0] at the ]0,1[ side of the Stern-Brocot Tree (A007305/A007306).at n=35A065674
- Sum of the first n safe primes.at n=30A066869
- a(n) = (2^n + 1)^2 - 2.at n=6A093069
- Number of sum of squares representations of n^2 in n dimensions disregarding order and sign.at n=18A105152
- Number of nonempty subsets of {1, 1/2, 1/3, ..., 1/n} that sum to an integer.at n=44A111233
- Number of nonempty subsets of {1, 1/2, 1/3, ..., 1/n} that sum to an integer.at n=45A111233
- Number of nonempty subsets of {1, 1/2, 1/3, ..., 1/n} that sum to an integer.at n=46A111233
- Smallest m such that A116361(m) = n.at n=15A116362
- Numbers k such that 10*(11*10^k - 1) + 1 is prime.at n=10A123372
- Expansion of x*(2 - 7*x + 2*x^2)/((1-x)*(1-4*x)*(1-2*x)).at n=7A130567
- A sequence of asymptotic density zeta(9) - 1, where zeta is the Riemann zeta function.at n=33A143035
- Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >= 3n.at n=15A210368
- Maximal size of a Binary Decision Diagram (or BDD) of index n.at n=16A327461
- Numbers k such that A163511(k) is a seventh power.at n=12A366287