28249638 has 16 divisors (see below), whose sum is σ = 56861040. Its totient is φ = 9356256.

The previous prime is 28249621. The next prime is 28249643. The reversal of 28249638 is 83694282.

It is a self number, because there is not a number n which added to its sum of digits gives 28249638.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 14053 + ... + 15936.

It is an arithmetic number, because the mean of its divisors is an integer number (3553815).

Almost surely, 2^28249638 is an apocalyptic number.

28249638 is an abundant number, since it is smaller than the sum of its proper divisors (28611402).

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

28249638 is a wasteful number, since it uses less digits than its factorization.

28249638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30151.

The product of its digits is 165888, while the sum is 42.

The square root of 28249638 is about 5315.0388521628. The cubic root of 28249638 is about 304.5586665471.

The spelling of 28249638 in words is "twenty-eight million, two hundred forty-nine thousand, six hundred thirty-eight".