12721637328 has 40 divisors (see below), whose sum is σ = 33354749088. Its totient is φ = 4177252992.

The previous prime is 12721637311. The next prime is 12721637363. The reversal of 12721637328 is 82373612721.

It is a happy number.

12721637328 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 12721637328.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1974651 + ... + 1981082.

Almost surely, 2^12721637328 is an apocalyptic number.

It is an amenable number.

12721637328 is an abundant number, since it is smaller than the sum of its proper divisors (20633111760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12721637328 is a wasteful number, since it uses less digits than its factorization.

12721637328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3955811 (or 3955805 counting only the distinct ones).

The product of its digits is 169344, while the sum is 42.

The spelling of 12721637328 in words is "twelve billion, seven hundred twenty-one million, six hundred thirty-seven thousand, three hundred twenty-eight".