28639216 has 10 divisors (see below), whose sum is σ = 55488512. Its totient is φ = 14319600.

The previous prime is 28639207. The next prime is 28639223. The reversal of 28639216 is 61293682.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 894960 + ... + 894991.

Almost surely, 2^28639216 is an apocalyptic number.

It is an amenable number.

28639216 is a deficient number, since it is larger than the sum of its proper divisors (26849296).

28639216 is a wasteful number, since it uses less digits than its factorization.

28639216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1789959 (or 1789953 counting only the distinct ones).

The product of its digits is 31104, while the sum is 37.

The square root of 28639216 is about 5351.5620149635. The cubic root of 28639216 is about 305.9522901111.

The spelling of 28639216 in words is "twenty-eight million, six hundred thirty-nine thousand, two hundred sixteen".