8581
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8582
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 8580
- Möbius Function
- -1
- Radical
- 8581
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 78
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1069
- 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 23.at n=36A020362
- Primes that remain prime through 3 iterations of function f(x) = 9x + 8.at n=27A023298
- Primes that remain prime through 4 iterations of the function f(x) = 9x + 8.at n=8A023326
- Least m such that if r and s in {1/4, 1/8, 1/12, ..., 1/4n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=35A024839
- Primes of the form j^2 + (j+1)^2.at n=23A027862
- Lower prime of a pair of consecutive primes having a difference of 16.at n=27A031934
- "BFJ" (reversible, size, labeled) transform of 2,1,1,1...at n=9A032039
- Least prime in A031934 (lesser of 16-twins) whose distance to the next 16-twin is 6*n.at n=8A052357
- McKay-Thompson series of class 30d for Monster.at n=32A058625
- a(n) = (2*n-1)^2 + (2*n)^2.at n=32A060820
- Numbers p from A001125 such that 2*p-3 is prime.at n=14A063939
- Numbers having exactly six anti-divisors.at n=35A066472
- a(n) = (prime(n)^2 + 1)/2.at n=30A066885
- Prime hypotenuses of Pythagorean triangles with a prime leg.at n=10A067756
- a(n) = (11*n^2 - 11*n + 2)/2.at n=39A069125
- a(0)=0, a(1)=1, a(n)=a(n-1)+a(n-2)+a(n-3) if a(n-1) is even, a(n)=a(n-1)+a(n-2) if a(n-1) is odd.at n=18A078513
- a(n) = 8*n^2 - 4*n + 1.at n=33A080856
- Third row of Pascal-(1,5,1) array A081580.at n=22A081589
- Primes of the form (4*k + 1)^2 + (4*k + 2)^2 where k=0,1,2,3,...at n=6A087871
- Primes p such that (p-11)/10 is also a prime.at n=37A089442