28993638 has 8 divisors (see below), whose sum is σ = 57987288. Its totient is φ = 9664544.

The previous prime is 28993637. The next prime is 28993693. The reversal of 28993638 is 83639982.

It is a sphenic number, since it is the product of 3 distinct primes.

28993638 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28993637) 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, 2416131 + ... + 2416142.

It is an arithmetic number, because the mean of its divisors is an integer number (7248411).

Almost surely, 2^28993638 is an apocalyptic number.

28993638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28993638 is a wasteful number, since it uses less digits than its factorization.

28993638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4832278.

The product of its digits is 559872, while the sum is 48.

The square root of 28993638 is about 5384.5740778635. The cubic root of 28993638 is about 307.2092141673.

The spelling of 28993638 in words is "twenty-eight million, nine hundred ninety-three thousand, six hundred thirty-eight".