8563
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
- 8564
- 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
- 8562
- Möbius Function
- -1
- Radical
- 8563
- 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
- 127
- 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
- 1067
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes of the form m^2 + 3m + 9, where m can be positive or negative.at n=28A005471
- 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=25A031589
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 64 ones.at n=7A031832
- Upper prime of a difference of 20 between consecutive primes.at n=11A031939
- Numbers whose base-5 representation contains exactly three 2's and three 3's.at n=7A045277
- Discriminants of imaginary quadratic fields with class number 9 (negated).at n=30A046006
- a(n) is the index of the smallest triangular number containing exactly n 6's.at n=5A048361
- Digitally balanced numbers in both bases 2 and 3.at n=13A049361
- Primes with distinct digits in alphabetical order (in English).at n=32A053435
- Primes with 2 representations: p*q*r - 1 = u*v*w + 1 where p, q, r, u, v and w are primes.at n=25A063644
- a(n) is the smallest positive integer such that no term in S={a(1),...,a(n)}, n>=3, divides the sum of any two other distinct terms of S, after first initializing the sequence with a(1)=3 and a(2)=4.at n=39A068573
- Euler transform of A002487.at n=19A071019
- a(1) = 1, a(n) = smallest prime number not already used such that concatenation of a(k) and a(n) is composite for all k = 1 to n-1.at n=36A075612
- Primes p such that both p-1 and p+1 have at most 3 prime factors, counted with multiplicity; i.e., primes p such that bigomega(p-1) <= 3 and bigomega(p+1) <= 3, where bigomega(n) = A001222(n).at n=31A079153
- Primes such that the next n successive differences are identical.at n=12A087562
- Start with 1 and repeatedly reverse the digits and add 57 to get the next term.at n=19A118153
- Start with 1 and repeatedly reverse the digits and add 57 to get the next term.at n=43A118153
- Start with 1 and repeatedly reverse the digits and add 57 to get the next term.at n=31A118153
- Start with 1 and repeatedly reverse the digits and add 57 to get the next term.at n=7A118153
- Numbers k such that the k-th triangular number contains only digits {3,6,7}.at n=7A119195