28784867668 has 6 divisors (see below), whose sum is σ = 50373518426. Its totient is φ = 14392433832.

The previous prime is 28784867633. The next prime is 28784867669. The reversal of 28784867668 is 86676848782.

It can be written as a sum of positive squares in only one way, i.e., 27234240784 + 1550626884 = 165028^2 + 39378^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28784867597 and 28784867606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28784867669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3598108455 + ... + 3598108462.

Almost surely, 2^28784867668 is an apocalyptic number.

It is an amenable number.

28784867668 is a deficient number, since it is larger than the sum of its proper divisors (21588650758).

28784867668 is a wasteful number, since it uses less digits than its factorization.

28784867668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7196216921 (or 7196216919 counting only the distinct ones).

The product of its digits is 346816512, while the sum is 70.

The spelling of 28784867668 in words is "twenty-eight billion, seven hundred eighty-four million, eight hundred sixty-seven thousand, six hundred sixty-eight".