28311388 has 24 divisors (see below), whose sum is σ = 57344000. Its totient is φ = 11978928.

The previous prime is 28311379. The next prime is 28311391. The reversal of 28311388 is 88311382.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4188 + ... + 8611.

Almost surely, 2^28311388 is an apocalyptic number.

28311388 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28311388 is an abundant number, since it is smaller than the sum of its proper divisors (29032612).

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

28311388 is a wasteful number, since it uses less digits than its factorization.

28311388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12889 (or 12887 counting only the distinct ones).

The product of its digits is 9216, while the sum is 34.

The square root of 28311388 is about 5320.8446697869. The cubic root of 28311388 is about 304.7804134763.

The spelling of 28311388 in words is "twenty-eight million, three hundred eleven thousand, three hundred eighty-eight".