28015728 has 160 divisors (see below), whose sum is σ = 87494400. Its totient is φ = 7630848.

The previous prime is 28015717. The next prime is 28015777. The reversal of 28015728 is 82751082.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 201483 + ... + 201621.

It is an arithmetic number, because the mean of its divisors is an integer number (546840).

Almost surely, 2^28015728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28015728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43747200).

28015728 is an abundant number, since it is smaller than the sum of its proper divisors (59478672).

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

28015728 is a wasteful number, since it uses less digits than its factorization.

28015728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 28015728 is about 5292.9885697968. The cubic root of 28015728 is about 303.7157430587.

The spelling of 28015728 in words is "twenty-eight million, fifteen thousand, seven hundred twenty-eight".