28778856 has 32 divisors (see below), whose sum is σ = 72964800. Its totient is φ = 9457280.

The previous prime is 28778837. The next prime is 28778857. The reversal of 28778856 is 65887782.

It is a junction number, because it is equal to n+sod(n) for n = 28778799 and 28778808.

It is not an unprimeable number, because it can be changed into a prime (28778857) 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, 6741 + ... + 10148.

It is an arithmetic number, because the mean of its divisors is an integer number (2280150).

Almost surely, 2^28778856 is an apocalyptic number.

It is an amenable number.

28778856 is an abundant number, since it is smaller than the sum of its proper divisors (44185944).

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

28778856 is a wasteful number, since it uses less digits than its factorization.

28778856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16969 (or 16965 counting only the distinct ones).

The product of its digits is 1505280, while the sum is 51.

The square root of 28778856 is about 5364.5928084059. The cubic root of 28778856 is about 306.4487414137.

The spelling of 28778856 in words is "twenty-eight million, seven hundred seventy-eight thousand, eight hundred fifty-six".