28808840 has 16 divisors (see below), whose sum is σ = 64819980. Its totient is φ = 11523520.

The previous prime is 28808779. The next prime is 28808867. The reversal of 28808840 is 4880882.

It can be written as a sum of positive squares in 2 ways, for example, as 28793956 + 14884 = 5366^2 + 122^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28808794 and 28808803.

It is an unprimeable number.

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, 360071 + ... + 360150.

Almost surely, 2^28808840 is an apocalyptic number.

28808840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28808840 is an abundant number, since it is smaller than the sum of its proper divisors (36011140).

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

28808840 is a wasteful number, since it uses less digits than its factorization.

28808840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720232 (or 720228 counting only the distinct ones).

The product of its (nonzero) digits is 32768, while the sum is 38.

The square root of 28808840 is about 5367.3867011796. The cubic root of 28808840 is about 306.5551316722. Note that the first 3 decimals are identical.

The spelling of 28808840 in words is "twenty-eight million, eight hundred eight thousand, eight hundred forty".