9217
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9940
- Proper Divisor Sum (Aliquot Sum)
- 723
- 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
- 8496
- Möbius Function
- 1
- Radical
- 9217
- 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
- 47
- 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) = (n-1)*2^n + 1.at n=10A000337
- Numbers that are the sum of 10 positive 10th powers.at n=9A004810
- Truncated square numbers: 7*n^2 + 4*n + 1.at n=36A005892
- Pseudoprimes to base 96.at n=32A020224
- Strong pseudoprimes to base 96.at n=8A020322
- a(n) = d(n)/2, where d = A026040.at n=35A026041
- Numerators of continued fraction convergents to sqrt(89).at n=5A041158
- Sizes of successive balls in D_4 lattice.at n=30A046949
- a(n) = T(8,n), array T given by A048472.at n=8A048480
- a(n) = T(n,n), array T given by A048472.at n=8A048482
- Differences between numbers k such that k and k+1 have the same sum of divisors.at n=28A054001
- Numbers k such that prime(k+2)-(k+2)*tau(k+2) = prime(k-2)-(k-2)*tau(k-2) where tau(k) = A000005(k) is the number of divisors of k.at n=30A067354
- a(n) = 512*n + 1.at n=18A076338
- Duplicate of A000337.at n=10A082753
- a(n) = 2*a(n-1) - 1 with a(0) = 10.at n=10A083705
- a(n) is the first term of the first run of exactly n non-perfect-powers.at n=43A087646
- Maximal values of m=a^2+b^2=c^2+d^2 for each x=a+b+c+d=6*p (p=any odd prime).at n=10A093300
- Array T(n,k) read by antidiagonals: T(1,k) = 2^k-1 and recursively T(n,k) = T(n-1,k) + A000337(k-1), n,k >= 1.at n=75A104746
- a(n) = 16*n^2 + 1.at n=23A108211
- Triangle read by rows, generated from (..., 3, 2, 1).at n=64A108283