8543
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8544
- 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
- 8542
- Möbius Function
- -1
- Radical
- 8543
- 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
- 171
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1066
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Where the prime race among 7k+1, ..., 7k+6 changes leader.at n=45A007354
- Coordination sequence for alpha-Mn, Position Mn3.at n=24A009952
- Primes that remain prime through 3 iterations of function f(x) = 5x + 4.at n=19A023284
- 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=23A031589
- Lower prime of a difference of 20 between consecutive primes.at n=11A031938
- Numbers k such that 51*2^k+1 is prime.at n=31A032375
- Odd k for which k+2^m is composite for all m < k.at n=6A033919
- Primes with distinct digits in descending order.at n=40A052014
- Least prime in A031938 (lesser of primes differing by 20) whose distance to the next 20-twin is 6*n.at n=36A052359
- Primes with distinct digits in alphabetical order (in English).at n=31A053435
- Number of bipartite graphs with n vertices, no isolated vertices and a distinguished bipartite block, up to isomorphism.at n=8A055192
- A B_2 sequence: a(n) is the smallest prime such that the pairwise sums of distinct elements are all distinct.at n=44A062294
- Potential Sierpiński numbers: integers for which the smallest m > 2^10 in A040076 such that n*2^m+1 is prime (A050921).at n=34A064721
- Primes associated with groups in A076077.at n=23A076076
- Primes p such that the next prime after p can be obtained from p by adding the sum of the digits of p.at n=43A089824
- Numbers k such that numerator(Bernoulli(2*k)/(2*k)) is different from numerator(Bernoulli(2*k)/(2*k*(2*k-1))).at n=30A090495
- Primes p such that both prime(p) + prime(p+1) +/-1 are also primes.at n=40A093734
- Primes p = p_(n+1) such that p_n + p_(n+2) = 2*p_(n+1) + 16.at n=19A095651
- Square array A(row>=1, col>=1) by antidiagonals: A(r,c) contains the c:th prime p for which A037888(p)=(r-1).at n=27A095749
- Sophie Germain type primes where 7*Prime[n]=2*Prime[m]+1.at n=35A104165