28728456 has 48 divisors (see below), whose sum is σ = 75903600. Its totient is φ = 9036000.

The previous prime is 28728443. The next prime is 28728463. The reversal of 28728456 is 65482782.

It is a happy number.

It is a nialpdrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 114331 + ... + 114581.

It is an arithmetic number, because the mean of its divisors is an integer number (1581325).

Almost surely, 2^28728456 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 28728456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37951800).

28728456 is an abundant number, since it is smaller than the sum of its proper divisors (47175144).

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

28728456 is a wasteful number, since it uses less digits than its factorization.

28728456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530 (or 275 counting only the distinct ones).

The product of its digits is 215040, while the sum is 42.

The square root of 28728456 is about 5359.8932825197. The cubic root of 28728456 is about 306.2697437778.

The spelling of 28728456 in words is "twenty-eight million, seven hundred twenty-eight thousand, four hundred fifty-six".