28638172 has 48 divisors (see below), whose sum is σ = 54641664. Its totient is φ = 13104000.

The previous prime is 28638157. The next prime is 28638173. The reversal of 28638172 is 27183682.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28638173) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 218547 + ... + 218677.

It is an arithmetic number, because the mean of its divisors is an integer number (1138368).

Almost surely, 2^28638172 is an apocalyptic number.

It is an amenable number.

28638172 is a deficient number, since it is larger than the sum of its proper divisors (26003492).

28638172 is a wasteful number, since it uses less digits than its factorization.

28638172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250 (or 248 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 28638172 is about 5351.4644724599. The cubic root of 28638172 is about 305.9485723874.

The spelling of 28638172 in words is "twenty-eight million, six hundred thirty-eight thousand, one hundred seventy-two".