13723728021 has 36 divisors (see below), whose sum is σ = 21464849952. Its totient is φ = 8745778008.

The previous prime is 13723728017. The next prime is 13723728041. The reversal of 13723728021 is 12082732731.

13723728021 is a `hidden beast` number, since 1 + 372 + 3 + 7 + 280 + 2 + 1 = 666.

It is not a de Polignac number, because 13723728021 - 2² = 13723728017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13723728041) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8757180 + ... + 8758746.

It is an arithmetic number, because the mean of its divisors is an integer number (596245832).

Almost surely, 2^13723728021 is an apocalyptic number.

It is an amenable number.

13723728021 is a deficient number, since it is larger than the sum of its proper divisors (7741121931).

13723728021 is an frugal number, since it uses more digits than its factorization.

13723728021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3172 (or 1593 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The spelling of 13723728021 in words is "thirteen billion, seven hundred twenty-three million, seven hundred twenty-eight thousand, twenty-one".