990990173 has 2 divisors, whose sum is σ = 990990174. Its totient is φ = 990990172.

The previous prime is 990990149. The next prime is 990990289. The reversal of 990990173 is 371099099.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 554932249 + 436057924 = 23557^2 + 20882^2 .

It is a cyclic number.

It is not a de Polignac number, because 990990173 - 2¹⁰ = 990989149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990990103) 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, 495495086 + 495495087.

It is an arithmetic number, because the mean of its divisors is an integer number (495495087).

Almost surely, 2^990990173 is an apocalyptic number.

It is an amenable number.

990990173 is a deficient number, since it is larger than the sum of its proper divisors (1).

990990173 is an equidigital number, since it uses as much as digits as its factorization.

990990173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 137781, while the sum is 47.

The square root of 990990173 is about 31479.9963945360. The cubic root of 990990173 is about 996.9876592481.

The spelling of 990990173 in words is "nine hundred ninety million, nine hundred ninety thousand, one hundred seventy-three".