28081100 has 18 divisors (see below), whose sum is σ = 60936204. Its totient is φ = 11232400.

The previous prime is 28081099. The next prime is 28081117. The reversal of 28081100 is 118082.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 140306 + ... + 140505.

Almost surely, 2^28081100 is an apocalyptic number.

28081100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28081100 is an abundant number, since it is smaller than the sum of its proper divisors (32855104).

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

28081100 is a wasteful number, since it uses less digits than its factorization.

28081100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280825 (or 280818 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 28081100 is about 5299.1603108417. The cubic root of 28081100 is about 303.9517900235.

Adding to 28081100 its reverse (118082), we get a palindrome (28199182).

The spelling of 28081100 in words is "twenty-eight million, eighty-one thousand, one hundred".