8990771021 has 2 divisors, whose sum is σ = 8990771022. Its totient is φ = 8990771020.

The previous prime is 8990770963. The next prime is 8990771033. The reversal of 8990771021 is 1201770998.

8990771021 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 can be written as a sum of positive squares in only one way, i.e., 8947078921 + 43692100 = 94589^2 + 6610^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8990771021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8990771051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4495385510 + 4495385511.

It is an arithmetic number, because the mean of its divisors is an integer number (4495385511).

Almost surely, 2^8990771021 is an apocalyptic number.

It is an amenable number.

8990771021 is a deficient number, since it is larger than the sum of its proper divisors (1).

8990771021 is an equidigital number, since it uses as much as digits as its factorization.

8990771021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63504, while the sum is 44.

The square root of 8990771021 is about 94819.6763388275. The cubic root of 8990771021 is about 2079.3725780340.

The spelling of 8990771021 in words is "eight billion, nine hundred ninety million, seven hundred seventy-one thousand, twenty-one".