28704728 has 16 divisors (see below), whose sum is σ = 57961680. Its totient is φ = 13248288.

The previous prime is 28704727. The next prime is 28704737. The reversal of 28704728 is 82740782.

It is a super-2 number, since 2×28704728² = 1647922819107968, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28704691 and 28704700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28704727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137900 + ... + 138107.

It is an arithmetic number, because the mean of its divisors is an integer number (3622605).

Almost surely, 2^28704728 is an apocalyptic number.

It is an amenable number.

28704728 is an abundant number, since it is smaller than the sum of its proper divisors (29256952).

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

28704728 is a wasteful number, since it uses less digits than its factorization.

28704728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276026 (or 276022 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 28704728 is about 5357.6793483746. The cubic root of 28704728 is about 306.1854003409.

The spelling of 28704728 in words is "twenty-eight million, seven hundred four thousand, seven hundred twenty-eight".