28009238 has 4 divisors (see below), whose sum is σ = 42013860. Its totient is φ = 14004618.

The previous prime is 28009231. The next prime is 28009291. The reversal of 28009238 is 83290082.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28009231) 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 as a sum of consecutive naturals, namely, 7002308 + ... + 7002311.

It is an arithmetic number, because the mean of its divisors is an integer number (10503465).

Almost surely, 2^28009238 is an apocalyptic number.

28009238 is a deficient number, since it is larger than the sum of its proper divisors (14004622).

28009238 is a wasteful number, since it uses less digits than its factorization.

28009238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14004621.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 28009238 is about 5292.3754590921. The cubic root of 28009238 is about 303.6922887643.

The spelling of 28009238 in words is "twenty-eight million, nine thousand, two hundred thirty-eight".