8091820991 has 2 divisors, whose sum is σ = 8091820992. Its totient is φ = 8091820990.

The previous prime is 8091820963. The next prime is 8091821009. The reversal of 8091820991 is 1990281908.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8091820991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8091820391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4045910495 + 4045910496.

It is an arithmetic number, because the mean of its divisors is an integer number (4045910496).

Almost surely, 2^8091820991 is an apocalyptic number.

8091820991 is a deficient number, since it is larger than the sum of its proper divisors (1).

8091820991 is an equidigital number, since it uses as much as digits as its factorization.

8091820991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 47.

The square root of 8091820991 is about 89954.5495847764. The cubic root of 8091820991 is about 2007.6226598687.

The spelling of 8091820991 in words is "eight billion, ninety-one million, eight hundred twenty thousand, nine hundred ninety-one".