999663025321 has 2 divisors, whose sum is σ = 999663025322. Its totient is φ = 999663025320.

The previous prime is 999663025289. The next prime is 999663025343. The reversal of 999663025321 is 123520366999.

It is a happy number.

It is the 408180-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 967114896400 + 32548128921 = 983420^2 + 180411^2 .

It is a cyclic number.

It is not a de Polignac number, because 999663025321 - 2⁵ = 999663025289 is a prime.

It is not a weakly prime, because it can be changed into another prime (999663025021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499831512660 + 499831512661.

It is an arithmetic number, because the mean of its divisors is an integer number (499831512661).

Almost surely, 2^999663025321 is an apocalyptic number.

It is an amenable number.

999663025321 is a deficient number, since it is larger than the sum of its proper divisors (1).

999663025321 is an equidigital number, since it uses as much as digits as its factorization.

999663025321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4723920, while the sum is 55.

The spelling of 999663025321 in words is "nine hundred ninety-nine billion, six hundred sixty-three million, twenty-five thousand, three hundred twenty-one".