17809
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19440
- Proper Divisor Sum (Aliquot Sum)
- 1631
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16180
- Möbius Function
- 1
- Radical
- 17809
- 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
- 97
- 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 k such that the period of the continued fraction for sqrt(k) contains exactly 74 ones.at n=18A031842
- Denominators of continued fraction convergents to sqrt(266).at n=6A041499
- Expansion of (1+x^2)*(1+x^5)/( Product_{j=1..7} (1-x^j) ).at n=40A060962
- Numbers in ascending order formed by using all the digits of the next n numbers.at n=17A081991
- Average of row n of A082259.at n=24A082262
- sigma(n) + n is a square.at n=35A114069
- Number of second differences of arrays of length 4 of numbers in 0..n.at n=41A228219
- a(n) = 10*n^2 + 4*n + 1.at n=42A272039
- Number of doublerises in all bargraphs having semiperimeter n (n>=2). A doublerise in a bargraph is any pair of adjacent up steps.at n=9A273714
- a(n) = Catalan(n) + 2^n - n - 1.at n=10A338726
- Numbers k that can be written as the sum of a perfect square and a factorial in at least 2 distinct ways.at n=31A358071