13728396321 has 8 divisors (see below), whose sum is σ = 20338364960. Its totient is φ = 9152264196.

The previous prime is 13728396317. The next prime is 13728396347. The reversal of 13728396321 is 12369382731.

13728396321 is a `hidden beast` number, since 1 + 3 + 7 + 2 + 8 + 3 + 9 + 632 + 1 = 666.

It is not a de Polignac number, because 13728396321 - 2² = 13728396317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13728396421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254229535 + ... + 254229588.

It is an arithmetic number, because the mean of its divisors is an integer number (2542295620).

Almost surely, 2^13728396321 is an apocalyptic number.

It is an amenable number.

13728396321 is a deficient number, since it is larger than the sum of its proper divisors (6609968639).

13728396321 is an equidigital number, since it uses as much as digits as its factorization.

13728396321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508459132 (or 508459126 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The spelling of 13728396321 in words is "thirteen billion, seven hundred twenty-eight million, three hundred ninety-six thousand, three hundred twenty-one".