28778884686 has 64 divisors (see below), whose sum is σ = 66580315200. Its totient is φ = 9203096448.

The previous prime is 28778884669. The next prime is 28778884723. The reversal of 28778884686 is 68648887782.

28778884686 is a `hidden beast` number, since 2 + 87 + 7 + 8 + 88 + 468 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 187336 + ... + 304388.

It is an arithmetic number, because the mean of its divisors is an integer number (1040317425).

Almost surely, 2^28778884686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28778884686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33290157600).

28778884686 is an abundant number, since it is smaller than the sum of its proper divisors (37801430514).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28778884686 is a wasteful number, since it uses less digits than its factorization.

28778884686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117250 (or 117244 counting only the distinct ones).

The product of its digits is 462422016, while the sum is 72.

The spelling of 28778884686 in words is "twenty-eight billion, seven hundred seventy-eight million, eight hundred eighty-four thousand, six hundred eighty-six".