990521977 has 2 divisors, whose sum is σ = 990521978. Its totient is φ = 990521976.

The previous prime is 990521971. The next prime is 990522019. The reversal of 990521977 is 779125099.

990521977 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 can be written as a sum of positive squares in only one way, i.e., 763748496 + 226773481 = 27636^2 + 15059^2 .

It is a cyclic number.

It is not a de Polignac number, because 990521977 - 2⁷ = 990521849 is a prime.

It is a super-2 number, since 2×990521977² = 1962267573839977058, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 990521977.

It is not a weakly prime, because it can be changed into another prime (990521971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495260988 + 495260989.

It is an arithmetic number, because the mean of its divisors is an integer number (495260989).

Almost surely, 2^990521977 is an apocalyptic number.

It is an amenable number.

990521977 is a deficient number, since it is larger than the sum of its proper divisors (1).

990521977 is an equidigital number, since it uses as much as digits as its factorization.

990521977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 357210, while the sum is 49.

The square root of 990521977 is about 31472.5591110733. The cubic root of 990521977 is about 996.8306246721.

The spelling of 990521977 in words is "nine hundred ninety million, five hundred twenty-one thousand, nine hundred seventy-seven".