28681689928 has 32 divisors (see below), whose sum is σ = 54391885560. Its totient is φ = 14177612800.

The previous prime is 28681689919. The next prime is 28681689943. The reversal of 28681689928 is 82998618682.

It can be written as a sum of positive squares in 4 ways, for example, as 23951276644 + 4730413284 = 154762^2 + 68778^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 520800 + ... + 573232.

Almost surely, 2^28681689928 is an apocalyptic number.

It is an amenable number.

28681689928 is a deficient number, since it is larger than the sum of its proper divisors (25710195632).

28681689928 is a wasteful number, since it uses less digits than its factorization.

28681689928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53217 (or 53213 counting only the distinct ones).

The product of its digits is 47775744, while the sum is 67.

The spelling of 28681689928 in words is "twenty-eight billion, six hundred eighty-one million, six hundred eighty-nine thousand, nine hundred twenty-eight".