9541
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11520
- Proper Divisor Sum (Aliquot Sum)
- 1979
- 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
- 7728
- Möbius Function
- -1
- Radical
- 9541
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 104
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- a(n) = floor(tau*a(n-2)) + a(n-1) with a(0)=0 and a(1)=1.at n=17A005833
- Pisot sequence E(4,19), a(n) = floor( a(n-1)^2/a(n-2)+1/2 ).at n=5A010907
- Numbers k such that the continued fraction for sqrt(k) has period 84.at n=34A020423
- Graham-Sloane-type lower bound on the size of a ternary (n,3,5) constant-weight code.at n=14A030505
- a(1) = 3; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=46A033681
- Numbers k such that sigma(k+1) = 2*phi(k).at n=10A067260
- Numbers n such that concatenation of n and its 10's complement is a palindrome.at n=7A109625
- Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 3 and repeat; as m = 1,2,3,.. the remaining terms form this sequence.at n=15A112561
- Diagonal immediately above the main diagonal of square array A130523.at n=6A130525
- Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X3 el 1,1 1,2 1,3 2,3 3,3 in any orientation.at n=12A146034
- Last term where no prime sums occur in A161190 in a 4-diagonal set of 24 terms.at n=2A161193
- a(n) = (4*n^3 - 9*n^2 + 11*n + 3)/3.at n=20A161707
- a(n) = Sum_{k=1..n} k*k', where n' is the arithmetic derivative of n.at n=31A190117
- Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of max{i(j+1-1),j(i+1)-1} (A203998).at n=47A203999
- Composite squarefree numbers n such that p(i)+4 divides n-4, where p(i) are the prime factors of n.at n=1A225714
- a(n) is the least number k such that Sum_{j=S(n)+1..S(n)+k} 1/j >= 1/2, where S(n) = Sum_{i=1..n-1} a(i) and S(1) = 0.at n=19A245800
- The broken eggs problem.at n=22A256101
- Irregular triangle read by rows: T(n,m) = number of lattice paths of type {B^Q}_R terminating at point (n, m).at n=53A291086
- Anagrasum integers: integers N that exactly reproduce their set of digits when we form the set of sums of pairs of adjacent digits.at n=23A296521
- Number of n X n 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=3A301444