28728504 has 144 divisors (see below), whose sum is σ = 96033600. Its totient is φ = 7709184.

The previous prime is 28728503. The next prime is 28728523. The reversal of 28728504 is 40582782.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28728503) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 59737 + ... + 60215.

It is an arithmetic number, because the mean of its divisors is an integer number (666900).

Almost surely, 2^28728504 is an apocalyptic number.

28728504 is a gapful number since it is divisible by the number (24) 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 28728504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48016800).

28728504 is an abundant number, since it is smaller than the sum of its proper divisors (67305096).

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

28728504 is a wasteful number, since it uses less digits than its factorization.

28728504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522 (or 508 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 28728504 is about 5359.8977602189. The cubic root of 28728504 is about 306.2699143513.

The spelling of 28728504 in words is "twenty-eight million, seven hundred twenty-eight thousand, five hundred four".