990989057 has 2 divisors, whose sum is σ = 990989058. Its totient is φ = 990989056.

The previous prime is 990989039. The next prime is 990989117. The reversal of 990989057 is 750989099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 858255616 + 132733441 = 29296^2 + 11521^2 .

It is a cyclic number.

It is not a de Polignac number, because 990989057 - 2²⁴ = 974211841 is a prime.

It is a super-2 number, since 2×990989057² = 1964118622187498498, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 990988993 and 990989011.

It is not a weakly prime, because it can be changed into another prime (990989257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495494528 + 495494529.

It is an arithmetic number, because the mean of its divisors is an integer number (495494529).

Almost surely, 2^990989057 is an apocalyptic number.

It is an amenable number.

990989057 is a deficient number, since it is larger than the sum of its proper divisors (1).

990989057 is an equidigital number, since it uses as much as digits as its factorization.

990989057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1837080, while the sum is 56.

The square root of 990989057 is about 31479.9786689890. The cubic root of 990989057 is about 996.9872849966.

The spelling of 990989057 in words is "nine hundred ninety million, nine hundred eighty-nine thousand, fifty-seven".