16590
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 46080
- Proper Divisor Sum (Aliquot Sum)
- 29490
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3744
- Möbius Function
- -1
- Radical
- 16590
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 5
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 97
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = floor(n*(n+2)*(2*n-1)/8).at n=39A007518
- Values of m, the main key or generating number for Pythagorean triangles in which S (the odd short leg) and U (the hypotenuse) are twin primes.at n=38A051891
- Sequence of sums based on primes = 7 mod 8.at n=28A060108
- a(1) = 1 and for n > 1 let a(n) = a(n-1) + m, where m is the arithmetic mean of the largest subset of all predecessors such that m is an integer and m is maximal.at n=36A063676
- a(3) = 2, a(4) = 3; for n > 4, a(n) = {a(n-2)}+{a(n-1)}, where {a} means largest prime <= a.at n=20A065435
- n times the n-th n-gonal number.at n=14A117665
- Numbers n such that Lucas(prime(n)) is prime, where Lucas = A000032.at n=45A120561
- Number of fixed hexagonal polygons (or benzenoids) with n cells.at n=7A121220
- Records for unitary abundant numbers, i.e., those integers which set a record for having a greater unitary abundance than any of their predecessors.at n=39A129499
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (0, 0, 1), (0, 1, -1), (0, 1, 1), (1, 0, 0)}.at n=7A151103
- One-half of averages of twin prime pairs of A001318.at n=15A154565
- Triangle of coefficients of polynomials v(n,x) jointly generated with A209773; see the Formula section.at n=48A209776
- Number of partitions of n into distinct parts with boundary size 8.at n=36A227565
- Triangular array read by rows: row n shows the coefficients of the polynomial u(n) = c(0) + c(1)*x + ... + c(n)*x^(n) which is the numerator of the n-th convergent of the continued fraction [k, k, k, ... ], where k = (x + 1)/(x + 2).at n=38A231774
- Numbers n such that smallest number not dividing n^2 (A236454) is different from smallest prime not dividing n (A053669).at n=39A235921
- a(n) = (2*n-1)*210; numbers which are 210 times an odd number.at n=39A236432
- Smallest number k such that k*n +/- 1 and k*n^2 +/- 1 are two sets of twin primes. a(n) = 0 if no such number exists.at n=52A239020
- Number of strings of length n over a 3-letter alphabet that do not begin with a nontrivial palindrome.at n=10A252696
- a(n) = A000203(A251720(n)).at n=8A268733
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 910", based on the 5-celled von Neumann neighborhood.at n=37A273764