28728320 has 88 divisors (see below), whose sum is σ = 71530368. Its totient is φ = 11059200.

The previous prime is 28728319. The next prime is 28728341. The reversal of 28728320 is 2382782.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 158630 + ... + 158810.

Almost surely, 2^28728320 is an apocalyptic number.

28728320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28728320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35765184).

28728320 is an abundant number, since it is smaller than the sum of its proper divisors (42802048).

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

28728320 is a wasteful number, since it uses less digits than its factorization.

28728320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 28728320 is about 5359.8805956849. The cubic root of 28728320 is about 306.2692604852.

The spelling of 28728320 in words is "twenty-eight million, seven hundred twenty-eight thousand, three hundred twenty".