8309
domain: N
Properties
Digital Properties
- Digit Count
- 4
- 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
- 9504
- Proper Divisor Sum (Aliquot Sum)
- 1195
- 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
- 7116
- Möbius Function
- 1
- Radical
- 8309
- 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
- 65
- 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
- a(n) = floor(exp(1/2)*n!).at n=6A030799
- a(n) = floor(47*(n-3/2)^(3/2)).at n=31A050256
- Number of bracelet structures using a maximum of four different colored beads.at n=11A056354
- Number of primes between n^4 and (n+1)^4.at n=30A061235
- a(n) is the least x such that the n values x+0, x+6, x+12, ..., x+6*(n-1) are all products of exactly two primes (i.e., semiprimes).at n=8A091016
- Fundamental discriminants of real quadratic number fields with class number 5.at n=39A094614
- Number of partitions of n with more even parts than odd parts.at n=39A108949
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1111-0110 pattern in any orientation.at n=9A146617
- Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (-1, 1), (0, 1), (1, -1), (1, 1)}.at n=8A151452
- Sum of first n isolated (or single) primes A007510.at n=37A153478
- a(n) = 8*n^2 + 20*n + 1.at n=31A161617
- Partial sums of A027642.at n=29A173242
- Odd nonprimes n such that n+d+1 is prime for all divisors d of n.at n=22A187554
- Number of 0..n arrays x(0..4) of 5 elements with zero 3rd differences.at n=39A200083
- Number of partitions of n+3 with largest inscribed rectangle having area <= n.at n=29A218624
- Numbers of form D^2 + 4d, with D odd, d divides D, and 1 < d < D.at n=46A237604
- Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=5A252150
- Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=0A252155
- T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=15A252157
- T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=20A252157