28253840 has 20 divisors (see below), whose sum is σ = 65690364. Its totient is φ = 11301504.

The previous prime is 28253831. The next prime is 28253857. The reversal of 28253840 is 4835282.

It can be written as a sum of positive squares in 2 ways, for example, as 14622976 + 13630864 = 3824^2 + 3692^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 28253797 and 28253806.

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 3 ways as a sum of consecutive naturals, for example, 176507 + ... + 176666.

Almost surely, 2^28253840 is an apocalyptic number.

28253840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28253840 is an abundant number, since it is smaller than the sum of its proper divisors (37436524).

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

28253840 is a wasteful number, since it uses less digits than its factorization.

28253840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353186 (or 353180 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 28253840 is about 5315.4341309060. The cubic root of 28253840 is about 304.5737663521.

The spelling of 28253840 in words is "twenty-eight million, two hundred fifty-three thousand, eight hundred forty".