9509
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9804
- Proper Divisor Sum (Aliquot Sum)
- 295
- 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
- 9216
- Möbius Function
- 1
- Radical
- 9509
- 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
- 52
- 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 such that ten iterations of Reverse and Add are needed to reach a palindrome.at n=7A015991
- Numbers k such that the continued fraction for sqrt(k) has period 27.at n=39A020366
- Recip transform of 2*(1 + x^3)-1/(1-x).at n=8A049151
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 7.at n=17A051972
- Numbers which need ten 'Reverse and Add' steps to reach a palindrome.at n=7A065215
- Numbers n such that 3*10^n + 2*R_n + 7 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=13A102968
- Numbers n such that the sum of the first n odd composites is palindromic in base 2.at n=10A118128
- a(n) = n*(7*n-2).at n=37A135703
- Semiprimes p*q such that 2^p mod q == 2^q mod p.at n=41A179707
- Semiprimes p*q with p < q and 2^p (mod q) == 2^q (mod p).at n=16A179839
- Take first n bits of the infinite Fibonacci word A003849, regard them as a binary number, then convert it to base 10.at n=14A182028
- First differences of A182028.at n=14A214319
- Least k such that phi(k) has exactly n divisors.at n=32A276044
- Numerators of coefficients of odd powers of x in expansion of f(x) = x cos (x cos (x cos( ... .at n=4A309204
- Draw the lines with equations y=kx (k=1..n) on the R^2/Z^2 square flat torus. a(n) is the number of intersection points.at n=50A334087
- Numbers that are the sum of nine fourth powers in exactly seven ways.at n=27A345849
- Number of integer partitions of n whose length is twice their alternating sum.at n=52A357709