990173517623 has 2 divisors, whose sum is σ = 990173517624. Its totient is φ = 990173517622.

The previous prime is 990173517589. The next prime is 990173517643. The reversal of 990173517623 is 326715371099.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 990173517623 - 2⁸ = 990173517367 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990173517643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495086758811 + 495086758812.

It is an arithmetic number, because the mean of its divisors is an integer number (495086758812).

Almost surely, 2^990173517623 is an apocalyptic number.

990173517623 is a deficient number, since it is larger than the sum of its proper divisors (1).

990173517623 is an equidigital number, since it uses as much as digits as its factorization.

990173517623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2143260, while the sum is 53.

The spelling of 990173517623 in words is "nine hundred ninety billion, one hundred seventy-three million, five hundred seventeen thousand, six hundred twenty-three".