990055771 has 2 divisors, whose sum is σ = 990055772. Its totient is φ = 990055770.

The previous prime is 990055763. The next prime is 990055777. The reversal of 990055771 is 177550099.

990055771 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (177550099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 990055771 - 2³ = 990055763 is a prime.

It is not a weakly prime, because it can be changed into another prime (990055777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495027885 + 495027886.

It is an arithmetic number, because the mean of its divisors is an integer number (495027886).

Almost surely, 2^990055771 is an apocalyptic number.

990055771 is a deficient number, since it is larger than the sum of its proper divisors (1).

990055771 is an equidigital number, since it uses as much as digits as its factorization.

990055771 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 99225, while the sum is 43.

The square root of 990055771 is about 31465.1516919909. The cubic root of 990055771 is about 996.6742083721.

The spelling of 990055771 in words is "nine hundred ninety million, fifty-five thousand, seven hundred seventy-one".