28388903 has 4 divisors (see below), whose sum is σ = 28537728. Its totient is φ = 28240080.

The previous prime is 28388881. The next prime is 28388909. The reversal of 28388903 is 30988382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28388903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28388909) 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, 74126 + ... + 74507.

It is an arithmetic number, because the mean of its divisors is an integer number (7134432).

Almost surely, 2^28388903 is an apocalyptic number.

28388903 is a deficient number, since it is larger than the sum of its proper divisors (148825).

28388903 is a wasteful number, since it uses less digits than its factorization.

28388903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148824.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 28388903 is about 5328.1237785922. The cubic root of 28388903 is about 305.0583172551.

The spelling of 28388903 in words is "twenty-eight million, three hundred eighty-eight thousand, nine hundred three".