28239393 has 48 divisors (see below), whose sum is σ = 47667840. Its totient is φ = 14556672.

The previous prime is 28239391. The next prime is 28239413. The reversal of 28239393 is 39393282.

It is not a de Polignac number, because 28239393 - 2¹ = 28239391 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28239391) 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 47 ways as a sum of consecutive naturals, for example, 259023 + ... + 259131.

It is an arithmetic number, because the mean of its divisors is an integer number (993080).

Almost surely, 2^28239393 is an apocalyptic number.

It is an amenable number.

28239393 is a deficient number, since it is larger than the sum of its proper divisors (19428447).

28239393 is a wasteful number, since it uses less digits than its factorization.

28239393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 205 counting only the distinct ones).

The product of its digits is 69984, while the sum is 39.

The square root of 28239393 is about 5314.0749900618. The cubic root of 28239393 is about 304.5218450628.

The spelling of 28239393 in words is "twenty-eight million, two hundred thirty-nine thousand, three hundred ninety-three".