8491
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
- 4
- Divisor Sum
- 9712
- Proper Divisor Sum (Aliquot Sum)
- 1221
- 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
- 7272
- Möbius Function
- 1
- Radical
- 8491
- 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
- 109
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 74.at n=22A020413
- Numbers k such that 95*2^k+1 is prime.at n=27A032397
- Take list of squares, move left digit of each term to end of previous term.at n=44A032760
- Smallest value of x such that M(x) = n, where M() is Mertens's function A002321.at n=28A051400
- Prefixing, suffixing or inserting a 9 in the number anywhere gives a prime.at n=35A069833
- G.f.: (1-x)^5/((-1+4*x-3*x^2+x^3)*(1-3*x+x^2)*(-1+2*x)).at n=7A089932
- Semiprimes in A103374.at n=17A103394
- Coefficients of the C-Dyson Mod 27 identity.at n=34A104503
- Number of 9-almost primes less than or equal to 10^n.at n=6A120050
- Least semiprime s for which the Mertens function M(s) = n.at n=32A123173
- a(n) = 4*3^n - 2*2^n - 1.at n=7A135914
- Let f(m) = number of steps needed to reach a Harshad number when the map k->A062028(l) is iterated starting at m; a(n) = smallest m such that f(m) = n.at n=79A181664
- Number of -n..n circular arrays x(0..4) of 5 elements with zero sums of x(i) and x(i)*x((i+1) mod 5).at n=41A202007
- Numbers that end in (..., 128, 128, 128, ...) under the rule: next term = product of the last four digits in the sequence so far.at n=37A240967
- a(n) = (n + 1)*(6*n^2 + 15*n + 4)/2.at n=13A269232
- Numbers m such that the decimal digits of m are exactly the same as those of all the indices corresponding to the prime factors of m.at n=10A287916
- Number T(n,k) of multisets of exactly k nonempty words with a total of n letters over n-ary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=69A293808
- Number of multisets of exactly three nonempty words with a total of n letters over n-ary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.at n=8A294005
- Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(Product_{j=1..n} (1+x^j) - 1).at n=61A294250
- E.g.f.: exp((1+x)*(1+x^2)*(1+x^3)*(1+x^4) - 1).at n=6A294252