18199849948321 has 2 divisors, whose sum is σ = 18199849948322. Its totient is φ = 18199849948320.

The previous prime is 18199849948207. The next prime is 18199849948337. The reversal of 18199849948321 is 12384994899181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9559777588321 + 8640072360000 = 3091889^2 + 2939400^2 .

It is a cyclic number.

It is not a de Polignac number, because 18199849948321 - 2²⁷ = 18199715730593 is a prime.

It is not a weakly prime, because it can be changed into another prime (18199849918321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099924974160 + 9099924974161.

It is an arithmetic number, because the mean of its divisors is an integer number (9099924974161).

Almost surely, 2^{18199849948321} is an apocalyptic number.

It is an amenable number.

18199849948321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18199849948321 is an equidigital number, since it uses as much as digits as its factorization.

18199849948321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 322486272, while the sum is 76.

The spelling of 18199849948321 in words is "eighteen trillion, one hundred ninety-nine billion, eight hundred forty-nine million, nine hundred forty-eight thousand, three hundred twenty-one".