28312121306 has 24 divisors (see below), whose sum is σ = 49407683220. Its totient is φ = 12132312192.

The previous prime is 28312121287. The next prime is 28312121359. The reversal of 28312121306 is 60312121382.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 28311091081 + 1030225 = 168259^2 + 1015^2 .

It is a Curzon number.

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, 1364546 + ... + 1385138.

Almost surely, 2^28312121306 is an apocalyptic number.

28312121306 is a deficient number, since it is larger than the sum of its proper divisors (21095561914).

28312121306 is a wasteful number, since it uses less digits than its factorization.

28312121306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34638 (or 34631 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

Adding to 28312121306 its reverse (60312121382), we get a palindrome (88624242688).

The spelling of 28312121306 in words is "twenty-eight billion, three hundred twelve million, one hundred twenty-one thousand, three hundred six".