28778408166 has 16 divisors (see below), whose sum is σ = 57559097664. Its totient is φ = 9592422504.

The previous prime is 28778408161. The next prime is 28778408173. The reversal of 28778408166 is 66180487782.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28778408161) 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 in 7 ways as a sum of consecutive naturals, for example, 99601 + ... + 259763.

It is an arithmetic number, because the mean of its divisors is an integer number (3597443604).

Almost surely, 2^28778408166 is an apocalyptic number.

28778408166 is an abundant number, since it is smaller than the sum of its proper divisors (28780689498).

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

28778408166 is a wasteful number, since it uses less digits than its factorization.

28778408166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190115.

The product of its (nonzero) digits is 7225344, while the sum is 57.

The spelling of 28778408166 in words is "twenty-eight billion, seven hundred seventy-eight million, four hundred eight thousand, one hundred sixty-six".