10805
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12972
- Proper Divisor Sum (Aliquot Sum)
- 2167
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8640
- Möbius Function
- 1
- Radical
- 10805
- 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
- 117
- 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
- Number of distinct products i*j with 0 <= i, j <= n-th prime.at n=44A027419
- Numerators of continued fraction convergents to sqrt(665).at n=8A042278
- a(n) = (2*n-1)^2 + (2*n)^2.at n=36A060820
- Expansion of 1/(1-x+x^2-2*x^3).at n=33A077951
- a(n) = 8*n^2 - 4*n + 1.at n=37A080856
- If p(k) is the k-th prime, then the n-th set of 3 consecutive cousin prime pairs starts at p(a(n)).at n=20A095970
- Column k=2 sequence of array A103728.at n=33A103729
- Expansion of (1+2*x^3)/(1-x+x^3-2*x^4).at n=35A103750
- Values x corresponding to the records d in A179406.at n=10A179407
- Number of (n+3) X 8 binary arrays with every 4 X 4 subblock commuting with each horizontal and vertical neighbor 4 X 4 subblock.at n=9A188101
- (9*7^n+1)/2.at n=4A199486
- Numbers k^2 + (k+1)^2 that can be expressed as a sum of two squares in exactly one other way.at n=31A239527
- Number of length n+3 0..4 arrays with every four consecutive terms having the sum of some three elements equal to three times the fourth.at n=31A248533
- Number of length 3 1..(n+2) arrays with no leading partial sum equal to a prime.at n=28A254541
- a(n) = r*a(ceiling(n/2))+s*a(floor(n/2)) with a(1)=1 and (r,s)=(4,1).at n=37A268527
- Subsequence of centered square numbers obtained by adding four triangles from A276914 and a central element, a(n) = 4*A276914(n) + 1.at n=37A276916
- Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = number of normalized 2n-plets associated to trees with k edges.at n=38A294439
- Solution (a(n)) of the complementary equation in Comments.at n=36A298877
- a(n) = A048673(n^2).at n=49A337336
- Denominator of (1+sigma(s)) / ((s+1)/2), where s is the square of n prime-shifted once (s = A003961(n)^2 = A003961(n^2)).at n=49A337339