991528207 has 2 divisors, whose sum is σ = 991528208. Its totient is φ = 991528206.

The previous prime is 991528199. The next prime is 991528231. The reversal of 991528207 is 702825199.

991528207 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (702825199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991528207 - 2³ = 991528199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991528607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495764103 + 495764104.

It is an arithmetic number, because the mean of its divisors is an integer number (495764104).

Almost surely, 2^991528207 is an apocalyptic number.

991528207 is a deficient number, since it is larger than the sum of its proper divisors (1).

991528207 is an equidigital number, since it uses as much as digits as its factorization.

991528207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 991528207 is about 31488.5408839470. The cubic root of 991528207 is about 997.1680566676.

The spelling of 991528207 in words is "nine hundred ninety-one million, five hundred twenty-eight thousand, two hundred seven".