28129728641 has 16 divisors (see below), whose sum is σ = 32762683008. Its totient is φ = 23650598400.

The previous prime is 28129728611. The next prime is 28129728661. The reversal of 28129728641 is 14682792182.

It is a cyclic number.

It is not a de Polignac number, because 28129728641 - 2¹⁰ = 28129727617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28129728641.

It is not an unprimeable number, because it can be changed into a prime (28129728611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2402321 + ... + 2414001.

It is an arithmetic number, because the mean of its divisors is an integer number (2047667688).

Almost surely, 2^28129728641 is an apocalyptic number.

It is an amenable number.

28129728641 is a deficient number, since it is larger than the sum of its proper divisors (4632954367).

28129728641 is a wasteful number, since it uses less digits than its factorization.

28129728641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18232.

The product of its digits is 774144, while the sum is 50.

The spelling of 28129728641 in words is "twenty-eight billion, one hundred twenty-nine million, seven hundred twenty-eight thousand, six hundred forty-one".