9787
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9788
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 9786
- Möbius Function
- -1
- Radical
- 9787
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 197
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1207
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of labeled ordered partitions of an n-set into odd parts.at n=7A006154
- For any circular arrangement of 0..n-1, let S = sum of squares of every sum of two contiguous numbers; then a(n) = # of distinct values of S.at n=38A007773
- Coordination sequence for sigma-CrFe, Position Xd.at n=25A009959
- Numbers k such that the continued fraction for sqrt(k) has period 70.at n=37A020409
- Primes that remain prime through 3 iterations of function f(x) = 2x + 3.at n=20A023273
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 97.at n=36A031595
- Discriminants of imaginary quadratic fields with class number 11 (negated).at n=34A046008
- Numbers n such that n and n+4^k are all primes for k=1,2,3.at n=24A049493
- Primes p such that p^11 reversed is also prime.at n=39A059704
- Primes of the form Sum_{k=1..n} phi(prime(k)).at n=13A101302
- Primes with minimal digit = 7.at n=14A106107
- Primes having only {7, 8, 9} as digits.at n=16A106110
- Primes having only {6, 7, 8, 9} as digits.at n=44A106111
- Primes with digit sum = 31.at n=12A106767
- Record values in A079300 (number of shortest addition chains of n).at n=12A118387
- Primes for which the weight as defined in A117078 is 9 and the gap as defined in A001223 is 4.at n=35A119594
- Mother primes of order 10.at n=43A136069
- Primes of the form 43x^2+2xy+43y^2.at n=35A140041
- Primes congruent to 22 mod 31.at n=39A142026
- Primes congruent to 19 mod 37.at n=34A142128