28564240 has 40 divisors (see below), whose sum is σ = 66703320. Its totient is φ = 11375616.

The previous prime is 28564219. The next prime is 28564271. The reversal of 28564240 is 4246582.

It can be written as a sum of positive squares in 4 ways, for example, as 2676496 + 25887744 = 1636^2 + 5088^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21516 + ... + 22804.

It is an arithmetic number, because the mean of its divisors is an integer number (1667583).

Almost surely, 2^28564240 is an apocalyptic number.

28564240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28564240 is an abundant number, since it is smaller than the sum of its proper divisors (38139080).

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

28564240 is a wasteful number, since it uses less digits than its factorization.

28564240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1579 (or 1573 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 31.

The square root of 28564240 is about 5344.5523666627. The cubic root of 28564240 is about 305.6850676442.

The spelling of 28564240 in words is "twenty-eight million, five hundred sixty-four thousand, two hundred forty".