28508520 has 32 divisors (see below), whose sum is σ = 85525920. Its totient is φ = 7602240.

The previous prime is 28508503. The next prime is 28508551. The reversal of 28508520 is 2580582.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 118666 + ... + 118905.

It is an arithmetic number, because the mean of its divisors is an integer number (2672685).

Almost surely, 2^28508520 is an apocalyptic number.

28508520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28508520 is an abundant number, since it is smaller than the sum of its proper divisors (57017400).

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

28508520 is a wasteful number, since it uses less digits than its factorization.

28508520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237585 (or 237581 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 30.

The square root of 28508520 is about 5339.3370374982. The cubic root of 28508520 is about 305.4861725781.

The spelling of 28508520 in words is "twenty-eight million, five hundred eight thousand, five hundred twenty".