9801
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 15
- Divisor Sum
- 16093
- Proper Divisor Sum (Aliquot Sum)
- 6292
- 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
- 5940
- Möbius Function
- 0
- Radical
- 33
- Omega Function (Ω)
- 6
- 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
- yes
- Perfect Cube
- no
- Pentagonal Number
- yes
- 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
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- no
- Perfect Power
- yes
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Take solution to Pellian equation x^2 - n*y^2 = 1 with smallest positive y and x >= 0; sequence gives a(n) = x, or 1 if n is a square. A002349 gives values of y.at n=28A002350
- a(n) = n^2 written backwards.at n=32A002942
- Numbers of the form 3^i*11^j.at n=22A003597
- a(n) = a(n-1) + a(n - 1 - number of even terms so far).at n=42A006336
- Non-Hamiltonian 1-tough simplicial polyhedra with n nodes.at n=16A007031
- Squares of palindromes.at n=18A014186
- Odd pentagonal numbers.at n=40A014632
- Expansion of 1/((1-3*x)*(1-9*x)).at n=4A016142
- a(n) = (3*n)^2.at n=33A016766
- a(n) = (4n + 3)^2.at n=24A016838
- a(n) = (5*n + 4)^2.at n=19A016898
- a(n) = (6*n+3)^2.at n=16A016946
- a(n) = (7*n + 1)^2.at n=14A016994
- a(n) = (8n + 3)^2.at n=12A017102
- a(n) = (9*n)^2.at n=11A017162
- a(n) = (10*n + 9)^2.at n=9A017378
- a(n) = (11*n)^2.at n=9A017390
- a(n) = (12*n + 3)^2.at n=8A017558
- Duplicate of A024537.at n=10A018905
- a(n) = floor( a(n-1)/(sqrt(2) - 1) ), with a(0) = 1.at n=11A024537