28685449728 has 640 divisors, whose sum is σ = 99726950400. Its totient is φ = 8062156800.

The previous prime is 28685449721. The next prime is 28685449733. The reversal of 28685449728 is 82794458682.

28685449728 is a `hidden beast` number, since 2 + 8 + 68 + 544 + 9 + 7 + 28 = 666.

It is not an unprimeable number, because it can be changed into a prime (28685449721) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 105850233 + ... + 105850503.

It is an arithmetic number, because the mean of its divisors is an integer number (155823360).

Almost surely, 2^28685449728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28685449728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49863475200).

28685449728 is an abundant number, since it is smaller than the sum of its proper divisors (71041500672).

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

28685449728 is a wasteful number, since it uses less digits than its factorization.

28685449728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361 (or 339 counting only the distinct ones).

The product of its digits is 61931520, while the sum is 63.

The spelling of 28685449728 in words is "twenty-eight billion, six hundred eighty-five million, four hundred forty-nine thousand, seven hundred twenty-eight".