16904
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 31710
- Proper Divisor Sum (Aliquot Sum)
- 14806
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8448
- Möbius Function
- 0
- Radical
- 4226
- Omega Function (Ω)
- 4
- 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
- 84
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers n such that n is a substring of its square (both n and n squared in base 4) (written in base 10).at n=31A018828
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 65.at n=24A031563
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 65.at n=1A031743
- Numbers k such that z(k) = j(k), where z(k) = sopf(k - d(k)), j(k) = d(sopf(k) + k), sopf(k) = A008472(k) and d(k) = A000005(k).at n=22A063961
- Number of partitions of n in which number of least parts is equal to least part.at n=45A096403
- Number of partitions of n with parts occurring at most thrice and an even number of parts. Row sums of A098489.at n=47A098491
- Number of partitions of n with parts occurring at most thrice and an odd number of parts. Row sums of A098490.at n=47A098492
- Numbers n such that P(4n) is prime, where P(m) is the number of partitions of m.at n=42A111045
- Coefficients of the sum 1+ x/(1-x) + x^2/(1-x^2) + x^3/ ( (1-x)(1-x^2)) + x^4/ ( (1-x)(1-x^3) ) + x^5/ ( (1-x)(1-x^4) ) + x^5 /((1-x^2)(1-x^3)) + x^6/ ( (1-x)(1-x^2)(1-x^3)) + ...at n=45A178702
- Main diagonal starting k=2 of array A(k,n) = numbers n such that n^k - prime(n) is a prime.at n=39A213477
- Number of tilings of a 4 X n rectangle using T and Z tetrominoes.at n=15A233139
- The decimal values of binary sequences representing the "bits" form of adjacency matrices of non-isomorphic tournament graphs.at n=35A256373
- Expansion of psi(x^3) * psi(-x^3) * chi(-x) / phi(-x)^2 in powers of x where phi(), psi(), chi() are Ramanujan theta functions.at n=15A260547
- Number of nX2 arrays containing 2 copies of 0..n-1 with no element 1 greater than its north, west or northwest neighbor modulo n and the upper left element equal to 0.at n=5A266830
- T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with no element 1 greater than its north, west or northwest neighbor modulo n and the upper left element equal to 0.at n=26A266832
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 158", based on the 5-celled von Neumann neighborhood.at n=7A270334
- Numbers whose binary indices are all semiprimes.at n=40A371454
- Dirichlet convolution of A276086 (primorial base exp-function) with A055615 (Dirichlet inverse of n).at n=57A383286
- Numbers k such that A384247(k) = A384247(k+1).at n=30A385743