8207
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8520
- Proper Divisor Sum (Aliquot Sum)
- 313
- 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
- 7896
- Möbius Function
- 1
- Radical
- 8207
- 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
- 158
- 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
- Powers of fifth root of 5 rounded down.at n=28A018126
- a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p diving [ A*a(n)+B ] and p=2, A=2.00013, B=3.0.at n=20A029580
- Number of partitions in parts not of the form 17k, 17k+3 or 17k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 7 are greater than 1.at n=36A035964
- Numbers whose base-4 representation contains exactly four 0's and no 1's.at n=25A045033
- Numbers whose base-4 representation contains exactly four 0's and two 3's.at n=20A045083
- a(n) = smallest number > a(n-1) such that a(1)*a(2)*...*a(n) + 1 and a(1)*a(2)*...*a(n) - 1 are primes.at n=25A051956
- a(n) = 1 + 2^(n-1) + n for n > 0, a(0) = 2.at n=14A052968
- Numbers k such that x^k + x^5 + 1 is irreducible over GF(2).at n=26A057474
- Numbers k such that binomial(2k,k)+1 is prime.at n=31A066699
- Number of solutions (x,y,z,u,v,w) to x+y+z = u+v+w, 0<=x,y,z,u,v,w<=n-1, x>=y>=z, u>=v>=w.at n=12A071009
- a(1) = 9; a(n) is smallest number > a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=44A074345
- From P-positions in a certain game.at n=13A081691
- Numbers n such that the partition function A000041(k) is even and odd the same number of times for 0 <= k <= n.at n=26A098936
- Number of ON cells at n-th stage of three-dimensional version of the cellular automaton A160117 using cubes.at n=12A160379
- a(n) = smallest number that leads to a new fixed point under the base-2 Kaprekar map of A164884.at n=34A164887
- Numbers k such that |2^k - 57| is prime.at n=38A165778
- Numbers 1 through 10000 sorted lexicographically in binary representation.at n=39A190126
- Triangle read by rows: T(n,k) is the number of secondary structures of size n having k stacks of even length (n>=0, k>=0).at n=27A202848
- Number of secondary structures of size n having no stacks of even length.at n=14A202849
- Number of (n+1)X(2+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements.at n=2A251022