28320772428 has 72 divisors (see below), whose sum is σ = 78402214800. Its totient is φ = 8566379136.

The previous prime is 28320772421. The next prime is 28320772429. The reversal of 28320772428 is 82427702382.

It is not an unprimeable number, because it can be changed into a prime (28320772421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 485223 + ... + 540446.

It is an arithmetic number, because the mean of its divisors is an integer number (1088919650).

Almost surely, 2^28320772428 is an apocalyptic number.

It is an amenable number.

28320772428 is an abundant number, since it is smaller than the sum of its proper divisors (50081442372).

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

28320772428 is a wasteful number, since it uses less digits than its factorization.

28320772428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025751 (or 1025746 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 45.

The spelling of 28320772428 in words is "twenty-eight billion, three hundred twenty million, seven hundred seventy-two thousand, four hundred twenty-eight".