990008993 has 2 divisors, whose sum is σ = 990008994. Its totient is φ = 990008992.

The previous prime is 990008953. The next prime is 990009017. The reversal of 990008993 is 399800099.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 887027089 + 102981904 = 29783^2 + 10148^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990008993 is a prime.

It is not a weakly prime, because it can be changed into another prime (990008953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495004496 + 495004497.

It is an arithmetic number, because the mean of its divisors is an integer number (495004497).

Almost surely, 2^990008993 is an apocalyptic number.

It is an amenable number.

990008993 is a deficient number, since it is larger than the sum of its proper divisors (1).

990008993 is an equidigital number, since it uses as much as digits as its factorization.

990008993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 47.

The square root of 990008993 is about 31464.4083529311. The cubic root of 990008993 is about 996.6585112226.

The spelling of 990008993 in words is "nine hundred ninety million, eight thousand, nine hundred ninety-three".