16609
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17604
- Proper Divisor Sum (Aliquot Sum)
- 995
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15616
- Möbius Function
- 1
- Radical
- 16609
- 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
- 66
- 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
- Strong pseudoprimes to base 80.at n=15A020306
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 17.at n=5A031605
- Number of 3 X 3 stochastic matrices under row and column permutations.at n=45A052282
- Least number k such that (1+1/k)^k yields n digits of e (A001113).at n=4A105053
- Coefficients of the B-Rogers mod 14 identity.at n=41A105781
- Ulam's spiral (SSE spoke).at n=32A143839
- Binomial transform of A010054 (characteristic function of triangular numbers).at n=16A143961
- Expansion of x*(x^2+x-1)/(3*x^6-4*x^5+x^4-3*x^2+4*x-1).at n=9A193418
- Number of arrays of 4 integers in -n..n with sum zero and equal numbers of elements greater than zero and less than zero.at n=15A201812
- a(n) = ( 2*n*(2*n^2 + 9*n + 14) + (-1)^n - 1 )/16.at n=39A248851
- a(n) = 10^(prime(n)-1) mod prime(n)^2.at n=39A265012
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 502", based on the 5-celled von Neumann neighborhood.at n=32A272579
- Numbers k such that [prime(k), prime(k+1), prime(k+2)] = [1, 2, 3] mod 11.at n=23A302767
- Numbers k such that sigma_2(k^2 + 1) == 0 (mod k).at n=33A360105
- a(n) = n^2 + 2^(n-1).at n=14A362438
- a(n) is the smallest number which can be represented as the sum of three distinct nonzero n-gonal numbers in exactly n ways, or -1 if no such number exists.at n=6A374273
- Consecutive states of the linear congruential pseudo-random number generator 259*s mod 2^15 when started at s=1.at n=24A384194