28055239 has 4 divisors (see below), whose sum is σ = 29275056. Its totient is φ = 26835424.

The previous prime is 28055233. The next prime is 28055257. The reversal of 28055239 is 93255082.

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 28055239 - 2³ = 28055231 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 (28055231) 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, 609874 + ... + 609919.

It is an arithmetic number, because the mean of its divisors is an integer number (7318764).

Almost surely, 2^28055239 is an apocalyptic number.

28055239 is a deficient number, since it is larger than the sum of its proper divisors (1219817).

28055239 is a wasteful number, since it uses less digits than its factorization.

28055239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1219816.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 28055239 is about 5296.7196452144. The cubic root of 28055239 is about 303.8584542747.

The spelling of 28055239 in words is "twenty-eight million, fifty-five thousand, two hundred thirty-nine".