28191640100 has 72 divisors (see below), whose sum is σ = 66486447720. Its totient is φ = 10313671680.

The previous prime is 28191640097. The next prime is 28191640111. The reversal of 28191640100 is 104619182.

It can be written as a sum of positive squares in 12 ways, for example, as 3365856256 + 24825783844 = 58016^2 + 157562^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42224 + ... + 241176.

It is an arithmetic number, because the mean of its divisors is an integer number (923422885).

Almost surely, 2^28191640100 is an apocalyptic number.

28191640100 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 28191640100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33243223860).

28191640100 is an abundant number, since it is smaller than the sum of its proper divisors (38294807620).

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

28191640100 is a wasteful number, since it uses less digits than its factorization.

28191640100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199089 (or 199082 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 32.

The spelling of 28191640100 in words is "twenty-eight billion, one hundred ninety-one million, six hundred forty thousand, one hundred".