28717128 has 96 divisors (see below), whose sum is σ = 85924800. Its totient is φ = 8592000.

The previous prime is 28717127. The next prime is 28717159. The reversal of 28717128 is 82171782.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 28717092 and 28717101.

It is not an unprimeable number, because it can be changed into a prime (28717123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79813 + ... + 80171.

It is an arithmetic number, because the mean of its divisors is an integer number (895050).

Almost surely, 2^28717128 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 28717128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42962400).

28717128 is an abundant number, since it is smaller than the sum of its proper divisors (57207672).

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

28717128 is a wasteful number, since it uses less digits than its factorization.

28717128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483 (or 476 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 28717128 is about 5358.8364408703. The cubic root of 28717128 is about 306.2294831181.

It can be divided in two parts, 2871 and 7128, that added together give a palindrome (9999).

The spelling of 28717128 in words is "twenty-eight million, seven hundred seventeen thousand, one hundred twenty-eight".