28239938 has 16 divisors (see below), whose sum is σ = 42993720. Its totient is φ = 13910400.

The previous prime is 28239899. The next prime is 28239971. The reversal of 28239938 is 83993282.

It can be written as a sum of positive squares in 4 ways, for example, as 25877569 + 2362369 = 5087^2 + 1537^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61028 + ... + 61488.

Almost surely, 2^28239938 is an apocalyptic number.

28239938 is a deficient number, since it is larger than the sum of its proper divisors (14753782).

28239938 is a wasteful number, since it uses less digits than its factorization.

28239938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 853.

The product of its digits is 186624, while the sum is 44.

The square root of 28239938 is about 5314.1262687294. The cubic root of 28239938 is about 304.5238040679.

The spelling of 28239938 in words is "twenty-eight million, two hundred thirty-nine thousand, nine hundred thirty-eight".