28761821064 has 256 divisors, whose sum is σ = 85585920000. Its totient is φ = 8923799808.

The previous prime is 28761821063. The next prime is 28761821117. The reversal of 28761821064 is 46012816782.

28761821064 is a `hidden beast` number, since 2 + 8 + 7 + 618 + 21 + 0 + 6 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (28761821063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 72447714 + ... + 72448110.

It is an arithmetic number, because the mean of its divisors is an integer number (334320000).

Almost surely, 2^28761821064 is an apocalyptic number.

28761821064 is a gapful number since it is divisible by the number (24) 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 28761821064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42792960000).

28761821064 is an abundant number, since it is smaller than the sum of its proper divisors (56824098936).

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

28761821064 is a wasteful number, since it uses less digits than its factorization.

28761821064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The spelling of 28761821064 in words is "twenty-eight billion, seven hundred sixty-one million, eight hundred twenty-one thousand, sixty-four".