9271
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9472
- Proper Divisor Sum (Aliquot Sum)
- 201
- 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
- 9072
- Möbius Function
- 1
- Radical
- 9271
- 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
- 91
- 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
- a(n) = floor(n*(n - 1)*(n - 2)/31).at n=67A011913
- Strong pseudoprimes to base 37.at n=9A020263
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 11 ones.at n=22A031779
- Numbers k > 1 such that k mod ord2(k) is even, where ord2(k) is the order of 2 mod k.at n=15A036260
- Numbers k such that sum of proper divisors or aliquot parts of k^2 (excluding 1) is a square, or A048050(k^2) is a square.at n=1A063900
- a(n) = sum_{k=1..n} prime(k)*prime(k+1).at n=13A074745
- Subminimal numbers, from minimal numbers by analogy with subfactorials.at n=44A079717
- Diagonal of triangular spiral in A051682.at n=45A081267
- Numbers n such that concatenation of n and its 10's complement is a palindrome.at n=4A109625
- Numbers k such that concatenation of k and its 10's complement is a palindromic prime.at n=2A109627
- a(n+3) = 6*a(n) - 5*a(n+2), a(0) = -1, a(1) = 1, a(2) = -5.at n=7A110210
- a(n) = (10^k - n)(10^k + n), where k is the number of digits in n.at n=26A110397
- Least number k > (2n-1) such that (2n-1)^k - 2 is prime, or 0 if no such number exists.at n=64A133856
- a(n) = 7^n mod 2^n.at n=15A138616
- Concatenation of first two digits and last two digits of n-th Mersenne prime A000668(n).at n=38A138863
- Number of distinct solutions of sum{i=1..2}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.at n=40A180794
- Monotonic ordering of nonnegative differences 10^i-3^j, for 40>=i>=0, j>=0.at n=18A192160
- [s(k)-s(j)]/5, where the pairs (k,j) are given by A205852 and A205853, and s(k) denotes the (k+1)-st Fibonacci number.at n=40A205855
- Nonprime numbers with all divisors with additive digital root of 1.at n=25A211822
- Odd integers n such that 2^n == 2^10 (mod n).at n=3A215612