28281808 has 20 divisors (see below), whose sum is σ = 54888228. Its totient is φ = 14117120.

The previous prime is 28281791. The next prime is 28281809. The reversal of 28281808 is 80818282.

It can be written as a sum of positive squares in 2 ways, for example, as 4545424 + 23736384 = 2132^2 + 4872^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28281809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12060 + ... + 14212.

Almost surely, 2^28281808 is an apocalyptic number.

It is an amenable number.

28281808 is a deficient number, since it is larger than the sum of its proper divisors (26606420).

28281808 is a wasteful number, since it uses less digits than its factorization.

28281808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2982 (or 2976 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 37.

The square root of 28281808 is about 5318.0643095021. The cubic root of 28281808 is about 304.6742306893.

The spelling of 28281808 in words is "twenty-eight million, two hundred eighty-one thousand, eight hundred eight".