8531
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9000
- Proper Divisor Sum (Aliquot Sum)
- 469
- 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
- 8064
- Möbius Function
- 1
- Radical
- 8531
- 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
- 171
- 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
- [ exp(10/19)*n! ].at n=6A030868
- 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 91.at n=21A031589
- Expansion of g.f.: Product_{n>0} 1/(1 - 2^(n-1)*x^n).at n=11A075900
- When this sequence is interleaved with its first differences and the resulting sequence is divided into blocks of 10 digits, each block contains 10 distinct digits. Each term is chosen to be the smallest that satisfies this property.at n=7A101246
- Triangle read by columns: number of n-node (unlabeled) graphs with girth k, for n >= 3, k >= 3.at n=47A128041
- Number of n-node (unlabeled) graphs with girth 5.at n=9A128238
- Number of partitions of n^3 into n distinct nonzero squares.at n=13A133102
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 1), (-1, 0), (0, -1), (1, -1), (1, 1)}.at n=7A151277
- The 4k+3 integers corresponding to the record positions in A165601.at n=31A166046
- a(n) = A030068(4n+3).at n=38A169740
- Number of ordered triples (w,x,y) with all terms in {1,...,n} and 2w^3>x^3+y^3.at n=26A211811
- Sum of numerators of Farey Sequence of order n.at n=42A213544
- Numbers not multiples of 9 whose digital sum coincides with digital sum of their largest proper divisor.at n=42A219340
- a(n) = Sum_{i=0..n} digsum_6(i)^3, where digsum_6(i) = A053827(i).at n=46A231674
- Number of compositions of n with exactly 4 transitions between different parts.at n=9A244716
- Binomial transform of A026007.at n=9A294502
- a(n) = 2^n + 2*n^2 + 1.at n=13A322593
- Numbers that are the sum of six fourth powers in three or more ways.at n=40A345560
- Numbers that are the sum of six fourth powers in exactly three ways.at n=37A345815
- Number of vertices in a Farey fan of order n.at n=45A360042