28304540 has 24 divisors (see below), whose sum is σ = 64843632. Its totient is φ = 10292480.

The previous prime is 28304539. The next prime is 28304557. The reversal of 28304540 is 4540382.

It is a super-2 number, since 2×28304540² = 1602293969223200, which contains 22 as substring.

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, 64109 + ... + 64548.

It is an arithmetic number, because the mean of its divisors is an integer number (2701818).

Almost surely, 2^28304540 is an apocalyptic number.

28304540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28304540 is an abundant number, since it is smaller than the sum of its proper divisors (36539092).

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

28304540 is a wasteful number, since it uses less digits than its factorization.

28304540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128677 (or 128675 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 28304540 is about 5320.2011240178. The cubic root of 28304540 is about 304.7558379171.

The spelling of 28304540 in words is "twenty-eight million, three hundred four thousand, five hundred forty".