9997
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 34
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10780
- Proper Divisor Sum (Aliquot Sum)
- 783
- 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
- 9216
- Möbius Function
- 1
- Radical
- 9997
- 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
- 179
- 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
- Pseudoprimes to base 19.at n=41A020147
- Strong pseudoprimes to base 19.at n=12A020245
- Numbers k such that the continued fraction for sqrt(k) has period 59.at n=11A020398
- a(1) = 7; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=32A025006
- a(n) = (n+1)*(5*n^2+4*n+1).at n=12A027849
- Numbers k such that k-th and (k+1)-st term of A038593 differ by 6.at n=43A038637
- Numbers having three 9's in base 10.at n=34A043527
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 19.at n=7A051984
- Numbers k such that k^2 contains only digits {0,4,9}, not ending with zero.at n=7A058443
- McKay-Thompson series of class 12G for Monster.at n=36A058485
- a(n) is the largest number which can be formed with no zeros, using least number of digits and having digit sum = n.at n=33A061219
- a(n) = smallest k such that 4k has a digit sum = n.at n=36A077490
- Number of unlabeled semitransitive orders on n elements: (1+3)-free posets.at n=8A079146
- Scale factor by which primitive Pythagorean triangle {x=A088509(n), y=A088510(n), z=A088511(n)} needs be enlarged in order to circumscribe the smallest integral square having a side on the hypotenuse.at n=15A088544
- Numbers k such that p(k), p(k)+6, p(k)+12, p(k)+18 are consecutive primes, where p(k) denotes k-th prime.at n=37A090832
- Numbers n such that if p=prime(n), then p, p+6, p+12, p+18 are consecutive primes with p=6*k+5 for some k, where prime(n) denotes n-th prime.at n=19A090835
- Near-repdigit semiprimes with 9 as repeated digit.at n=27A105990
- Composite numbers between largest n-digit prime and the smallest (n+1) digit prime.at n=40A109936
- Numbers k such that k concatenated with k-5 gives the product of two numbers which differ by 6.at n=9A116125
- n times n+6 gives the concatenation of two numbers m and m-8.at n=11A116237