9681
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14784
- Proper Divisor Sum (Aliquot Sum)
- 5103
- 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
- 5520
- Möbius Function
- -1
- Radical
- 9681
- 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
- 60
- 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) = n*(11*n - 1)/2.at n=42A022268
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=45A024846
- Numbers n such that 69*2^n-1 is prime.at n=42A050560
- G.f.: Sum_{n >= 1} x^n/(1-x^n)^5.at n=19A073570
- Diagonal in array of n-gonal numbers A081422.at n=20A081437
- Number of pairs with two different elements which can be obtained by selecting unique elements from two sets with n+1 and n^2 elements respectively and n common elements.at n=21A085490
- Number of partitions of n such that the size of the tail below the Durfee square is equal to the size of the tail to the right of the Durfee square.at n=53A114424
- The number of n-almost primes less than or equal to e^n, starting with a(0)=1.at n=25A116432
- G.f. satisfies: A(x) = 1 + (x+x^2)*A(x+x^2)^2.at n=7A127784
- a(n) = 6*n^2 - 10*n + 5.at n=40A136392
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, 0), (0, 1, 1), (1, 0, -1), (1, 0, 1)}.at n=7A150617
- a(n) = 242*n + 1.at n=39A157958
- a(n) = 484*n + 1.at n=19A158326
- a(n) = 20*n^2 + 1.at n=22A158493
- a(n) = 80*n^2 + 1.at n=11A158776
- Triangle of numerators of dual coefficients of Faulhaber.at n=49A201453
- Calendar Problem #27, April 2012 Mathematics Teacher.at n=2A208646
- Expansion of 1/(1-22*x+22*x^2-x^3).at n=3A212335
- a(n) = 5*n^2 + 1.at n=44A212656
- E.g.f. satisfies: A(x) = exp( x/(1 - x*A(x)^3) ).at n=5A212917