28666378806 has 32 divisors (see below), whose sum is σ = 61755589728. Its totient is φ = 8818621440.

The previous prime is 28666378757. The next prime is 28666378813. The reversal of 28666378806 is 60887366682.

It is a super-2 number, since 2×28666378806² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28666378806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 375430 + ... + 445286.

It is an arithmetic number, because the mean of its divisors is an integer number (1929862179).

Almost surely, 2^28666378806 is an apocalyptic number.

28666378806 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

28666378806 is an abundant number, since it is smaller than the sum of its proper divisors (33089210922).

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

28666378806 is a wasteful number, since it uses less digits than its factorization.

28666378806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75136.

The product of its (nonzero) digits is 27869184, while the sum is 60.

The spelling of 28666378806 in words is "twenty-eight billion, six hundred sixty-six million, three hundred seventy-eight thousand, eight hundred six".