28665777778 has 16 divisors (see below), whose sum is σ = 47150688096. Its totient is φ = 12962384640.

The previous prime is 28665777773. The next prime is 28665777781. The reversal of 28665777778 is 87777756682.

It is not an unprimeable number, because it can be changed into a prime (28665777773) 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, 3371376 + ... + 3379867.

It is an arithmetic number, because the mean of its divisors is an integer number (2946918006).

Almost surely, 2^28665777778 is an apocalyptic number.

28665777778 is a deficient number, since it is larger than the sum of its proper divisors (18484910318).

28665777778 is a wasteful number, since it uses less digits than its factorization.

28665777778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6751449.

The product of its digits is 387233280, while the sum is 70.

The spelling of 28665777778 in words is "twenty-eight billion, six hundred sixty-five million, seven hundred seventy-seven thousand, seven hundred seventy-eight".