19992012230321 has 2 divisors, whose sum is σ = 19992012230322. Its totient is φ = 19992012230320.

The previous prime is 19992012230273. The next prime is 19992012230347. The reversal of 19992012230321 is 12303221029991.

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., 10387213326400 + 9604798903921 = 3222920^2 + 3099161^2 .

It is an emirp because it is prime and its reverse (12303221029991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19992012230321 - 2³⁰ = 19990938488497 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19992012730321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9996006115160 + 9996006115161.

It is an arithmetic number, because the mean of its divisors is an integer number (9996006115161).

Almost surely, 2^{19992012230321} is an apocalyptic number.

It is an amenable number.

19992012230321 is a deficient number, since it is larger than the sum of its proper divisors (1).

19992012230321 is an equidigital number, since it uses as much as digits as its factorization.

19992012230321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 44.

The spelling of 19992012230321 in words is "nineteen trillion, nine hundred ninety-two billion, twelve million, two hundred thirty thousand, three hundred twenty-one".