28320645380 has 48 divisors (see below), whose sum is σ = 60916304064. Its totient is φ = 11053929600.

The previous prime is 28320645373. The next prime is 28320645383. The reversal of 28320645380 is 8354602382.

It is not an unprimeable number, because it can be changed into a prime (28320645383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 888194 + ... + 919526.

It is an arithmetic number, because the mean of its divisors is an integer number (1269089668).

Almost surely, 2^28320645380 is an apocalyptic number.

28320645380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28320645380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30458152032).

28320645380 is an abundant number, since it is smaller than the sum of its proper divisors (32595658684).

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

28320645380 is a wasteful number, since it uses less digits than its factorization.

28320645380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32436 (or 32434 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 41.

The spelling of 28320645380 in words is "twenty-eight billion, three hundred twenty million, six hundred forty-five thousand, three hundred eighty".