28720512 has 96 divisors (see below), whose sum is σ = 83776680. Its totient is φ = 9443328.

The previous prime is 28720507. The next prime is 28720513. The reversal of 28720512 is 21502782.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28720513) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 123148 + ... + 123380.

Almost surely, 2^28720512 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 28720512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41888340).

28720512 is an abundant number, since it is smaller than the sum of its proper divisors (55056168).

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

28720512 is a wasteful number, since it uses less digits than its factorization.

28720512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 28720512 is about 5359.1521717525. The cubic root of 28720512 is about 306.2415112460.

The spelling of 28720512 in words is "twenty-eight million, seven hundred twenty thousand, five hundred twelve".