8143
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
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8640
- Proper Divisor Sum (Aliquot Sum)
- 497
- 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
- 7648
- Möbius Function
- 1
- Radical
- 8143
- 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
- 158
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 72.at n=30A020411
- 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 89.at n=20A031587
- "AGK" (ordered, elements, unlabeled) transform of 1,3,5,7...at n=9A032026
- Number of partitions in parts not of the form 13k, 13k+1 or 13k-1. Also number of partitions with no part of size 1 and differences between parts at distance 5 are greater than 1.at n=43A035949
- Number of partitions satisfying cn(0,5) + cn(2,5) <= cn(1,5) + cn(4,5) and cn(0,5) + cn(3,5) <= cn(1,5) + cn(4,5).at n=33A039887
- Numbers whose base-5 representation contains exactly two 0's and three 3's.at n=20A045198
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 3.at n=45A050065
- a(1)=1, a(n) is the smallest integer > a(n-1) such that the largest element in the simple continued fraction for S(n)=1/a(1)+1/a(2)+...+1/a(n) equals 3n.at n=40A070899
- a(n) = n! * Sum_{i,j,k,l >= 0, i+j+k+l = n} 1/(i!*j!*k!*l!).at n=8A092429
- Number of prime pairs below 10^n having a difference of 4.at n=5A093737
- Numerators of "Farey fraction" approximations to Pi.at n=49A097545
- Leading diagonal of array in A100461.at n=13A100462
- a(n) = floor(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=10, a(2)=30.at n=25A104863
- One-seventh of the difference of squares of legs of primitive Pythagorean triangles, neither of which is a multiple of 7.at n=33A127924
- a(n) = 15*n^2 + 9*n + 1.at n=23A134153
- Numbers of length n binary words with fewer than 8 0-digits between any pair of consecutive 1-digits.at n=13A145116
- G.f.: x*(1+x+x^2)*(1+6*x+8*x^2+4*x^3-x^4)/((1+x)^2*(1-x)^4).at n=16A147691
- 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), (-1, 0, 1), (-1, 1, -1), (0, 1, 0), (1, 0, 0)}.at n=8A149926
- Multiples of 17 whose reversal - 1 is also a multiple of 17.at n=29A166398
- Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=6, k=1 and l=-1.at n=6A177175