28806688889 has 6 divisors (see below), whose sum is σ = 31663550730. Its totient is φ = 26187898880.

The previous prime is 28806688811. The next prime is 28806688907. The reversal of 28806688889 is 98888660882.

It can be written as a sum of positive squares in only one way, i.e., 28640485225 + 166203664 = 169235^2 + 12892^2 .

It is not a de Polignac number, because 28806688889 - 2¹² = 28806684793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28806681889) 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, 119035784 + ... + 119036025.

It is an arithmetic number, because the mean of its divisors is an integer number (5277258455).

Almost surely, 2^28806688889 is an apocalyptic number.

It is an amenable number.

28806688889 is a deficient number, since it is larger than the sum of its proper divisors (2856861841).

28806688889 is a wasteful number, since it uses less digits than its factorization.

28806688889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238071831 (or 238071820 counting only the distinct ones).

The product of its (nonzero) digits is 169869312, while the sum is 71.

The spelling of 28806688889 in words is "twenty-eight billion, eight hundred six million, six hundred eighty-eight thousand, eight hundred eighty-nine".