28120057728 has 64 divisors (see below), whose sum is σ = 85364469120. Its totient is φ = 8034301440.

The previous prime is 28120057717. The next prime is 28120057753. The reversal of 28120057728 is 82775002182.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 28120057728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5227978 + ... + 5233353.

It is an arithmetic number, because the mean of its divisors is an integer number (1333819830).

Almost surely, 2^28120057728 is an apocalyptic number.

28120057728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28120057728 is an abundant number, since it is smaller than the sum of its proper divisors (57244411392).

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

28120057728 is a wasteful number, since it uses less digits than its factorization.

28120057728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10461355 (or 10461343 counting only the distinct ones).

The product of its (nonzero) digits is 125440, while the sum is 42.

The spelling of 28120057728 in words is "twenty-eight billion, one hundred twenty million, fifty-seven thousand, seven hundred twenty-eight".