28403880 has 32 divisors (see below), whose sum is σ = 85212000. Its totient is φ = 7574336.

The previous prime is 28403863. The next prime is 28403929. The reversal of 28403880 is 8830482.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118230 + ... + 118469.

It is an arithmetic number, because the mean of its divisors is an integer number (2662875).

Almost surely, 2^28403880 is an apocalyptic number.

28403880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28403880 is an abundant number, since it is smaller than the sum of its proper divisors (56808120).

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

28403880 is a wasteful number, since it uses less digits than its factorization.

28403880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236713 (or 236709 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 28403880 is about 5329.5290598701. The cubic root of 28403880 is about 305.1119538844. Note that the first 3 decimals are identical.

The spelling of 28403880 in words is "twenty-eight million, four hundred three thousand, eight hundred eighty".