9641
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9984
- Proper Divisor Sum (Aliquot Sum)
- 343
- 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
- 9300
- Möbius Function
- 1
- Radical
- 9641
- 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
- 73
- 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
- Largest number not the sum of distinct n-th-order polygonal numbers.at n=31A007419
- Expansion of e.g.f.: exp(tanh(arcsin(x)))=1+x+1/2!*x^2-3/4!*x^4-4/5!*x^5+21/6!*x^6...at n=10A012255
- Pseudoprimes to base 95.at n=33A020223
- Numbers k such that the continued fraction for sqrt(k) has period 86.at n=24A020425
- Numbers whose base-4 representation contains exactly three 1's and four 2's.at n=18A045104
- Nonprime numbers k such that sum of aliquot divisors of k is a cube.at n=31A048698
- Composite numbers n such that k! == 1 (mod n) for some k > 2.at n=15A049048
- a(n) = 10*n^2+n.at n=30A055437
- Composite n such that both n and its reversal in base 10 are squarefree, none of the prime factors of n are palindromes and the prime factors of the reversal of n are the reversals of those of n.at n=1A083526
- a(n) is the shortest possible n-th-power loop where an n-th-power loop of length m > 1 is a circular permutation of the numbers 1 to m such that the sum of any two consecutive numbers is a perfect n-th power.at n=3A115418
- Difference between squares of legs of primitive Pythagorean triangles, sorted (with multiplicity).at n=26A127923
- Least number k > 1 (that is not the power of prime p) such that k divides (p+1)^k-1, where p = prime(n).at n=10A128356
- Least number k > n such that k^2 divides n^k - 1.at n=29A128452
- Composite numbers such that the square mean of their prime factors is a nonprime integer (where the prime factors are taken with multiplicity and the square mean of c and d is sqrt((c^2+d^2)/2)).at n=32A134602
- Positive numbers of the form x^4 - 6 * x^2 * y^2 + y^4 (where x,y are integers).at n=26A135789
- Numbers for which the root mean square of nontrivial divisors is an integer and which are not a square of prime numbers.at n=28A247137
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 20", based on the 5-celled von Neumann neighborhood.at n=40A269713
- Number of partitions p of n that contain a proper partition of the maximal part of p.at n=33A279036
- Numbers k such that (25*10^k - 67)/3 is prime.at n=17A293685
- Numbers k such that k!+1 reversed is a prime.at n=12A298702