28731928 has 16 divisors (see below), whose sum is σ = 53995680. Its totient is φ = 14333088.

The previous prime is 28731919. The next prime is 28731931. The reversal of 28731928 is 82913782.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 175 + ... + 7582.

It is an arithmetic number, because the mean of its divisors is an integer number (3374730).

Almost surely, 2^28731928 is an apocalyptic number.

It is an amenable number.

28731928 is a deficient number, since it is larger than the sum of its proper divisors (25263752).

28731928 is a wasteful number, since it uses less digits than its factorization.

28731928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8226 (or 8222 counting only the distinct ones).

The product of its digits is 48384, while the sum is 40.

The square root of 28731928 is about 5360.2171597800. The cubic root of 28731928 is about 306.2820814372.

The spelling of 28731928 in words is "twenty-eight million, seven hundred thirty-one thousand, nine hundred twenty-eight".