28389021680 has 20 divisors (see below), whose sum is σ = 66004475592. Its totient is φ = 11355608640.

The previous prime is 28389021679. The next prime is 28389021697. The reversal of 28389021680 is 8612098382.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177431306 + ... + 177431465.

Almost surely, 2^28389021680 is an apocalyptic number.

28389021680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28389021680 is an abundant number, since it is smaller than the sum of its proper divisors (37615453912).

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

28389021680 is a wasteful number, since it uses less digits than its factorization.

28389021680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354862784 (or 354862778 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 47.

The spelling of 28389021680 in words is "twenty-eight billion, three hundred eighty-nine million, twenty-one thousand, six hundred eighty".