28128828 has 48 divisors (see below), whose sum is σ = 80783360. Its totient is φ = 7418304.

The previous prime is 28128827. The next prime is 28128833. The reversal of 28128828 is 82882182.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28128827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11788 + ... + 13971.

Almost surely, 2^28128828 is an apocalyptic number.

28128828 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28128828 is an abundant number, since it is smaller than the sum of its proper divisors (52654532).

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

28128828 is a wasteful number, since it uses less digits than its factorization.

28128828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25786 (or 25784 counting only the distinct ones).

The product of its digits is 32768, while the sum is 39.

The square root of 28128828 is about 5303.6617539206. The cubic root of 28128828 is about 304.1238962901.

The spelling of 28128828 in words is "twenty-eight million, one hundred twenty-eight thousand, eight hundred twenty-eight".