17309
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18240
- Proper Divisor Sum (Aliquot Sum)
- 931
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16380
- Möbius Function
- 1
- Radical
- 17309
- 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
- 172
- 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
- Difference between two partition g.f.s.at n=13A007327
- a(n) = floor(C(2n,n)/2^(n+1)).at n=18A024504
- Composite numbers whose prime factors contain no digits other than 1 and 9.at n=15A036309
- Number of partitions of n with some part repeated.at n=36A047967
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 24.at n=50A051965
- Composite numbers whose divisors (except 1) all contain the digit 9.at n=29A062680
- Cardinality of set of sets of parts of all partitions of n.at n=47A088314
- Triangle read by rows: T(n,k) is the number of secondary structures of size n (n>=0) having k stacks of length 1 (k>=0).at n=57A202838
- Numbers n such that n!8-2 is prime.at n=54A204664
- Composite numbers whose concatenation of their aliquot parts, in ascending order, is a palindrome.at n=30A249300
- a(n) = n*(25*n - 39)/2.at n=38A263231
- Numbers with at least three digits and with the property that the sum of the cubes of the first and last digit equals the number obtained when the first and last digits are deleted.at n=33A275343
- Composite numbers k with its divisors having the property that the last digit of every divisor is the same as the first digit of the next divisor.at n=38A307858
- Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=15A318345
- Number of integer partitions of 2n containing at least one even part.at n=18A366527
- a(n) = Sum_{k=0..floor(n/3)} binomial(n-k,k)^2 * binomial(n-2*k,k).at n=10A383539
- Indices of records in A210693.at n=20A391871