28728538778 has 32 divisors (see below), whose sum is σ = 44791056000. Its totient is φ = 13808145600.

The previous prime is 28728538777. The next prime is 28728538781. The reversal of 28728538778 is 87783582782.

It is not an unprimeable number, because it can be changed into a prime (28728538777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3725675 + ... + 3733377.

It is an arithmetic number, because the mean of its divisors is an integer number (1399720500).

Almost surely, 2^28728538778 is an apocalyptic number.

28728538778 is a deficient number, since it is larger than the sum of its proper divisors (16062517222).

28728538778 is a wasteful number, since it uses less digits than its factorization.

28728538778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8342.

The product of its digits is 84295680, while the sum is 65.

The spelling of 28728538778 in words is "twenty-eight billion, seven hundred twenty-eight million, five hundred thirty-eight thousand, seven hundred seventy-eight".