28239587 has 4 divisors (see below), whose sum is σ = 28413000. Its totient is φ = 28066176.

The previous prime is 28239571. The next prime is 28239641. The reversal of 28239587 is 78593282.

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 28239587 - 2⁴ = 28239571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28239557) 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, 86462 + ... + 86787.

It is an arithmetic number, because the mean of its divisors is an integer number (7103250).

Almost surely, 2^28239587 is an apocalyptic number.

28239587 is a deficient number, since it is larger than the sum of its proper divisors (173413).

28239587 is a wasteful number, since it uses less digits than its factorization.

28239587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173412.

The product of its digits is 241920, while the sum is 44.

The square root of 28239587 is about 5314.0932434424. The cubic root of 28239587 is about 304.5225423996.

The spelling of 28239587 in words is "twenty-eight million, two hundred thirty-nine thousand, five hundred eighty-seven".