28729728 has 160 divisors (see below), whose sum is σ = 91083960. Its totient is φ = 8957952.

The previous prime is 28729717. The next prime is 28729769. The reversal of 28729728 is 82792782.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 176175 + ... + 176337.

Almost surely, 2^28729728 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 28729728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45541980).

28729728 is an abundant number, since it is smaller than the sum of its proper divisors (62354232).

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

28729728 is a wasteful number, since it uses less digits than its factorization.

28729728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206 (or 185 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 28729728 is about 5360.0119402852. The cubic root of 28729728 is about 306.2742639112.

The spelling of 28729728 in words is "twenty-eight million, seven hundred twenty-nine thousand, seven hundred twenty-eight".