16511
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19200
- Proper Divisor Sum (Aliquot Sum)
- 2689
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14040
- Möbius Function
- -1
- Radical
- 16511
- 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
- 71
- 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
- a(n) = floor(binomial(n,4)/4).at n=37A011850
- Strong pseudoprimes to base 94.at n=13A020320
- Numbers k such that k^2 is palindromic in base 4.at n=22A029986
- Number of reversible string structures with n beads using exactly two different colors.at n=15A056326
- a(n) = 4^n + 2^n - 1.at n=7A099393
- Numerator of sum of reciprocals of first n 5-simplex numbers A000389.at n=32A118431
- Partial sums of A001037, the number of degree-n irreducible polynomials over GF(2).at n=17A173270
- Composite squarefree numbers n such that p(i)-9 divides n+9, where p(i) are the prime factors of n.at n=40A225709
- a(n) = 120*n^3 + 60*n^2 + 2*n + 1.at n=5A272126
- Triangle read by rows T(n, m) = sigma^*_(n-m)(m), n >= 1, m = 1, 2, ..., n, with sigma^*_(k)(n) given in a comment in A279395.at n=58A279396
- Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 779", based on the 5-celled von Neumann neighborhood.at n=14A290297
- Numerators of r(n) := Sum_{k=0..n-1} 1/Product_{j=0..4} (k + j + 1), for n >= 0, with r(0) = 0.at n=33A300298
- First class of all proper positive solutions y1(n) = a(n) of the Pell equation x^2 - 7*y^2 = 9.at n=3A307169
- First term of n-th difference sequence of (floor(k*r)), r = sqrt(5), k >= 0.at n=16A325668
- Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x + 47^2)^2 = y^2.at n=7A332000
- Numbers of the form prime(w)*prime(x)*prime(y) with w >= x >= y such that 2w = 3x + 4y.at n=26A358102
- Dimension of space of equivariant linear maps from R^{n^3} to R^{n^3} under diagonal action of {-1, 1}^n.at n=11A370649
- Numbers m such that Stern polynomial B(m,x) has no irreducible polynomial factors that themselves are Stern polynomials. The initial a(1) = 1 is included by convention.at n=21A389918