28087439 has 4 divisors (see below), whose sum is σ = 29308656. Its totient is φ = 26866224.

The previous prime is 28087429. The next prime is 28087441. The reversal of 28087439 is 93478082.

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

It is a cyclic number.

It is not a de Polignac number, because 28087439 - 2⁸ = 28087183 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28087396 and 28087405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28087429) 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, 610574 + ... + 610619.

It is an arithmetic number, because the mean of its divisors is an integer number (7327164).

Almost surely, 2^28087439 is an apocalyptic number.

28087439 is a deficient number, since it is larger than the sum of its proper divisors (1221217).

28087439 is a wasteful number, since it uses less digits than its factorization.

28087439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1221216.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 28087439 is about 5299.7583907193. The cubic root of 28087439 is about 303.9746595625.

The spelling of 28087439 in words is "twenty-eight million, eighty-seven thousand, four hundred thirty-nine".