990173517589 has 2 divisors, whose sum is σ = 990173517590. Its totient is φ = 990173517588.

The previous prime is 990173517563. The next prime is 990173517623. The reversal of 990173517589 is 985715371099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 892240822225 + 97932695364 = 944585^2 + 312942^2 .

It is an emirp because it is prime and its reverse (985715371099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 990173517589 - 2¹⁵ = 990173484821 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 990173517589.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990173917589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495086758794 + 495086758795.

It is an arithmetic number, because the mean of its divisors is an integer number (495086758795).

Almost surely, 2^990173517589 is an apocalyptic number.

It is an amenable number.

990173517589 is a deficient number, since it is larger than the sum of its proper divisors (1).

990173517589 is an equidigital number, since it uses as much as digits as its factorization.

990173517589 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21432600, while the sum is 64.

The spelling of 990173517589 in words is "nine hundred ninety billion, one hundred seventy-three million, five hundred seventeen thousand, five hundred eighty-nine".