28381933 has 4 divisors (see below), whose sum is σ = 28723968. Its totient is φ = 28039900.

The previous prime is 28381919. The next prime is 28381939. The reversal of 28381933 is 33918382.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28381933 - 2¹⁷ = 28250861 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28381892 and 28381901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28381939) 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, 170893 + ... + 171058.

It is an arithmetic number, because the mean of its divisors is an integer number (7180992).

Almost surely, 2^28381933 is an apocalyptic number.

It is an amenable number.

28381933 is a deficient number, since it is larger than the sum of its proper divisors (342035).

28381933 is an equidigital number, since it uses as much as digits as its factorization.

28381933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342034.

The product of its digits is 31104, while the sum is 37.

The square root of 28381933 is about 5327.4696620441. The cubic root of 28381933 is about 305.0333493947.

The spelling of 28381933 in words is "twenty-eight million, three hundred eighty-one thousand, nine hundred thirty-three".