28685385878 has 16 divisors (see below), whose sum is σ = 44116727760. Its totient is φ = 13980432000.

The previous prime is 28685385877. The next prime is 28685385881. The reversal of 28685385878 is 87858358682.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28685385877) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62348 + ... + 247503.

It is an arithmetic number, because the mean of its divisors is an integer number (2757295485).

Almost surely, 2^28685385878 is an apocalyptic number.

28685385878 is a deficient number, since it is larger than the sum of its proper divisors (15431341882).

28685385878 is a wasteful number, since it uses less digits than its factorization.

28685385878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311023.

The product of its digits is 206438400, while the sum is 68.

The spelling of 28685385878 in words is "twenty-eight billion, six hundred eighty-five million, three hundred eighty-five thousand, eight hundred seventy-eight".