28320100 has 36 divisors (see below), whose sum is σ = 61847604. Its totient is φ = 11255680.

The previous prime is 28320091. The next prime is 28320119. The reversal of 28320100 is 102382.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1196836 + 27123264 = 1094^2 + 5208^2 .

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, 16482 + ... + 18118.

It is an arithmetic number, because the mean of its divisors is an integer number (1717989).

Almost surely, 2^28320100 is an apocalyptic number.

28320100 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 28320100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30923802).

28320100 is an abundant number, since it is smaller than the sum of its proper divisors (33527504).

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

28320100 is a wasteful number, since it uses less digits than its factorization.

28320100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1824 (or 1817 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 28320100 is about 5321.6632738271. The cubic root of 28320100 is about 304.8116726837.

Adding to 28320100 its reverse (102382), we get a palindrome (28422482).

The spelling of 28320100 in words is "twenty-eight million, three hundred twenty thousand, one hundred".