28280778 has 16 divisors (see below), whose sum is σ = 59538720. Its totient is φ = 8930736.

The previous prime is 28280761. The next prime is 28280779. The reversal of 28280778 is 87708282.

It is not an unprimeable number, because it can be changed into a prime (28280779) 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, 123925 + ... + 124152.

It is an arithmetic number, because the mean of its divisors is an integer number (3721170).

Almost surely, 2^28280778 is an apocalyptic number.

28280778 is an abundant number, since it is smaller than the sum of its proper divisors (31257942).

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

28280778 is a wasteful number, since it uses less digits than its factorization.

28280778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248101.

The product of its (nonzero) digits is 100352, while the sum is 42.

The square root of 28280778 is about 5317.9674688738. The cubic root of 28280778 is about 304.6705319834.

The spelling of 28280778 in words is "twenty-eight million, two hundred eighty thousand, seven hundred seventy-eight".