28678820 has 12 divisors (see below), whose sum is σ = 60225564. Its totient is φ = 11471520.

The previous prime is 28678801. The next prime is 28678823. The reversal of 28678820 is 2887682.

It can be written as a sum of positive squares in 2 ways, for example, as 5484964 + 23193856 = 2342^2 + 4816^2 .

It is not an unprimeable number, because it can be changed into a prime (28678823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 716951 + ... + 716990.

It is an arithmetic number, because the mean of its divisors is an integer number (5018797).

Almost surely, 2^28678820 is an apocalyptic number.

28678820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28678820 is an abundant number, since it is smaller than the sum of its proper divisors (31546744).

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

28678820 is a wasteful number, since it uses less digits than its factorization.

28678820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1433950 (or 1433948 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 41.

The square root of 28678820 is about 5355.2609646963. The cubic root of 28678820 is about 306.0932547875.

The spelling of 28678820 in words is "twenty-eight million, six hundred seventy-eight thousand, eight hundred twenty".