8170
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 15840
- Proper Divisor Sum (Aliquot Sum)
- 7670
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3024
- Möbius Function
- 1
- Radical
- 8170
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 52
- 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
- Number of integers with a shortest addition chain of length n.at n=17A003065
- Number of n-step self-avoiding walks on hexagonal lattice from (0,0) to (0,4).at n=5A005551
- Maxima of the rows of the triangle A259095.at n=40A005577
- 9-gonal (or enneagonal) pyramidal numbers: a(n) = n*(n+1)*(7*n-4)/6.at n=19A007584
- Pseudoprimes to base 11.at n=25A020139
- a(n) = (2*n+1)*(9*n+1).at n=21A033573
- 11-gonal (or hendecagonal) numbers: a(n) = n*(9*n-7)/2.at n=43A051682
- Number of ordered pairs of partitions of n with no common parts.at n=16A054440
- Add column entries of the table with rows (1,2,0,0...), (0,3,4,5,0,0...), (0,0,6,7,8,9,0,0...), (0,0,0,10,11,12,13,14,0,0...), ...at n=36A064694
- Even pseudoprimes to base 11.at n=4A090084
- Number of compositions of n with first part 2 and no equal adjacent parts; this is column 2 of the array in A096568.at n=19A096570
- Let f(x)=(largest digit of x)^(smallest digit of x) + x (A097385). Sequence gives numbers n such that f(n) and f(n+1) are both prime.at n=23A097387
- Number of partitions of n having no parts with multiplicity 3.at n=34A118807
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n having k LD's (n>=0; 0<=k<=floor((n-1)/2)).at n=40A128733
- Number of n X n symmetric binary matrices with every 1 adjacent to another 1 horizontally or vertically.at n=4A140425
- Number of permutations p of {1,...,n} satisfying p(1)=1 and, if n>1, |p(i)-p((i mod n)+1)| is in {2,3} for i from 1 to n.at n=41A174469
- a(n) is the smallest integer k such that sigma_2(k) = sigma_2(k + 2n), where sigma_2(k) is the sum of squares of divisors of k (A001157).at n=37A175199
- Where records occur in A169784.at n=36A175437
- Parameters n for which the Tate-Shafarevich group Ш of the elliptic curve y^2=x^3-n has order 16.at n=42A179140
- Let f(m) = number of steps needed to reach a Harshad number when the map k->A062028(l) is iterated starting at m; a(n) = smallest m such that f(m) = n.at n=95A181664