9120821791 has 2 divisors, whose sum is σ = 9120821792. Its totient is φ = 9120821790.

The previous prime is 9120821729. The next prime is 9120821819. The reversal of 9120821791 is 1971280219.

It is a strong prime.

It is an emirp because it is prime and its reverse (1971280219) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9120821791 - 2¹⁹ = 9120297503 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9120821191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4560410895 + 4560410896.

It is an arithmetic number, because the mean of its divisors is an integer number (4560410896).

Almost surely, 2^9120821791 is an apocalyptic number.

9120821791 is a deficient number, since it is larger than the sum of its proper divisors (1).

9120821791 is an equidigital number, since it uses as much as digits as its factorization.

9120821791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 40.

The square root of 9120821791 is about 95502.9936232368. The cubic root of 9120821791 is about 2089.3506060710.

The spelling of 9120821791 in words is "nine billion, one hundred twenty million, eight hundred twenty-one thousand, seven hundred ninety-one".