9791 has 2 divisors, whose sum is σ = 9792. Its totient is φ = 9790.
The previous prime is 9787. The next prime is 9803. The reversal of 9791 is 1979.
It is a weak prime.
It is an emirp because it is prime and its reverse (1979) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 9791 - 22 = 9787 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a plaindrome in base 12.
It is a self number, because there is not a number n which added to its sum of digits gives 9791.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (9721) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4895 + 4896.
It is an arithmetic number, because the mean of its divisors is an integer number (4896).
9791 is a deficient number, since it is larger than the sum of its proper divisors (1).
9791 is an equidigital number, since it uses as much as digits as its factorization.
9791 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 567, while the sum is 26.
The square root of 9791 is about 98.9494820603. The cubic root of 9791 is about 21.3931966611.
The spelling of 9791 in words is "nine thousand, seven hundred ninety-one".
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