638428184 has 16 divisors (see below), whose sum is σ = 1202283600. Its totient is φ = 317819232.

The previous prime is 638428163. The next prime is 638428187. The reversal of 638428184 is 481824836.

It is a super-2 number, since 2×638428184² = 815181092251075712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638428187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172412 + ... + 176075.

It is an arithmetic number, because the mean of its divisors is an integer number (75142725).

Almost surely, 2^638428184 is an apocalyptic number.

It is an amenable number.

638428184 is a deficient number, since it is larger than the sum of its proper divisors (563855416).

638428184 is a wasteful number, since it uses less digits than its factorization.

638428184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348722 (or 348718 counting only the distinct ones).

The product of its digits is 294912, while the sum is 44.

The square root of 638428184 is about 25267.1364424226. The cubic root of 638428184 is about 861.0678028929.

The spelling of 638428184 in words is "six hundred thirty-eight million, four hundred twenty-eight thousand, one hundred eighty-four".