9643
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
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9644
- 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
- 9642
- Möbius Function
- -1
- Radical
- 9643
- 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
- 166
- 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
- 1191
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = a(n-2) + a(n-3) + a(n-4), with initial values a(0) = 0, a(1) = 2, a(2) = 3, a(3) = 6.at n=23A001634
- Number of permutations of [n] with at least one strong fixed point (a permutation p of {1,2,...,n} is said to have j as a strong fixed point if p(k) < j for k < j and p(k) > j for k > j).at n=7A006932
- Primes that remain prime through 3 iterations of function f(x) = 8x + 9.at n=5A023295
- 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 97.at n=24A031595
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 54 ones.at n=30A031822
- a(n) = a(n-1)+ a(round(2*(n-1)/3)) +a(round((n-1)/3)) starting a(1)=1.at n=30A033498
- Discriminants of imaginary quadratic fields with class number 11 (negated).at n=33A046008
- Primes with distinct digits in descending order.at n=50A052014
- Primes p from A031924 such that A052180(primepi(p)) = 11.at n=22A052232
- Prime number spiral (clockwise, Southwest spoke).at n=17A054568
- Prime lucky numbers k (from A031157) such that nextprime(k)=nextlucky(k).at n=16A057698
- Primes with 2 representations: p*q*r - 1 = u*v*w + 1 where p, q, r, u, v and w are primes.at n=30A063644
- a(n) is the smallest number that cannot be obtained from the numbers {2^0,2^1,...,2^n} using each number at most once and the operators +, -, *, /. Parentheses are allowed, intermediate fractions are not allowed.at n=7A071314
- 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=36A079153
- Primes p such that 6p + 1 and (p-1)/6 are primes.at n=20A085957
- a(0) =1, a(1) = 2, a(n) = smallest prime beginning with the sum of two previous terms.at n=6A087543
- p(k) such that 2*p(k)+3 and 2*p(k+1) + 3 are consecutive primes, where p(i) denotes the i-th prime.at n=37A089527
- Evaluate n^4 - 93n^3 + 3196n^2 - 48008n + 265483 for n >= 0, record the primes.at n=12A095974
- Primes from merging of 4 successive digits in decimal expansion of exp(Pi).at n=39A105009
- Primes for which the weight as defined in A117078 is 23.at n=21A119504