28981903 has 4 divisors (see below), whose sum is σ = 28993888. Its totient is φ = 28969920.

The previous prime is 28981891. The next prime is 28981907. The reversal of 28981903 is 30918982.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28981903 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 (28981907) 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, 951 + ... + 7672.

It is an arithmetic number, because the mean of its divisors is an integer number (7248472).

Almost surely, 2^28981903 is an apocalyptic number.

28981903 is a deficient number, since it is larger than the sum of its proper divisors (11985).

28981903 is an equidigital number, since it uses as much as digits as its factorization.

28981903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11984.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 28981903 is about 5383.4842806495. The cubic root of 28981903 is about 307.1677615491.

The spelling of 28981903 in words is "twenty-eight million, nine hundred eighty-one thousand, nine hundred three".