28705788 has 18 divisors (see below), whose sum is σ = 72561944. Its totient is φ = 9568584.

The previous prime is 28705769. The next prime is 28705819. The reversal of 28705788 is 88750782.

It is a happy number.

28705788 is a `hidden beast` number, since 2 + 8 + 70 + 578 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 398656 + ... + 398727.

Almost surely, 2^28705788 is an apocalyptic number.

It is an amenable number.

28705788 is an abundant number, since it is smaller than the sum of its proper divisors (43856156).

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

28705788 is a wasteful number, since it uses less digits than its factorization.

28705788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797393 (or 797388 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 45.

The square root of 28705788 is about 5357.7782708880. The cubic root of 28705788 is about 306.1891692035.

The spelling of 28705788 in words is "twenty-eight million, seven hundred five thousand, seven hundred eighty-eight".