28107537821 has 6 divisors (see below), whose sum is σ = 30895062366. Its totient is φ = 25552307000.

The previous prime is 28107537811. The next prime is 28107537863. The reversal of 28107537821 is 12873570182.

It can be written as a sum of positive squares in only one way, i.e., 22796772196 + 5310765625 = 150986^2 + 72875^2 .

It is not a de Polignac number, because 28107537821 - 2³⁴ = 10927668637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28107537811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 116146730 + ... + 116146971.

It is an arithmetic number, because the mean of its divisors is an integer number (5149177061).

Almost surely, 2^28107537821 is an apocalyptic number.

It is an amenable number.

28107537821 is a deficient number, since it is larger than the sum of its proper divisors (2787524545).

28107537821 is a wasteful number, since it uses less digits than its factorization.

28107537821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232293723 (or 232293712 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 44.

The spelling of 28107537821 in words is "twenty-eight billion, one hundred seven million, five hundred thirty-seven thousand, eight hundred twenty-one".