17875
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 26208
- Proper Divisor Sum (Aliquot Sum)
- 8333
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12000
- Möbius Function
- 0
- Radical
- 715
- Omega Function (Ω)
- 5
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 97
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- 4-dimensional analog of centered polygonal numbers. Also number of regions created by sides and diagonals of a convex n-gon in general position.at n=27A006522
- Number of regions in regular n-gon with all diagonals drawn.at n=26A007678
- a(n) = (1/2)*(binomial(2n, n) - binomial(2n-2, n-1)).at n=7A024482
- a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| = 1 for i = 1,2,...,n and s(0) = 2. Also a(n) = sum of numbers in row n+1 of array T defined in A026009.at n=15A026010
- a(n) = A027082(n, 2n-2).at n=9A027089
- a(n) = greatest number in row n of array T given by A027082.at n=11A027102
- Odd numbers in the (1,2)-Pascal triangle A029635 that are different from 1.at n=58A029639
- Distinct odd numbers in the (1,2)-Pascal triangle A029635.at n=48A029642
- Numbers to the right of the central elements of the (1,2)-Pascal triangle A029635 that are different from 2.at n=49A029649
- Odd numbers to the right of the central elements of the (1,2)-Pascal triangle A029635.at n=29A029650
- Odd numbers in (2,1)-Pascal triangle A029653 that are different from 1.at n=56A029657
- Distinct odd numbers in (2,1)-Pascal triangle A029653.at n=47A029660
- Odd numbers to the left of the central elements of the (2,1)-Pascal triangle A029653.at n=35A029664
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 21 ones.at n=8A031789
- a(n) = (2*n+1)*(12*n+1).at n=27A033576
- A convolution triangle of numbers obtained from A025750.at n=17A049223
- a(n) = binomial(n+6,6)*(2n+7)/7.at n=9A050486
- (Terms in A029661)/2.at n=31A051430
- (Terms in A029647)/2.at n=38A051471
- Least k such that decimal representation of k*n contains only digits 0 and 5.at n=27A096684