638940328 has 32 divisors (see below), whose sum is σ = 1297837800. Its totient is φ = 294887424.

The previous prime is 638940319. The next prime is 638940331. The reversal of 638940328 is 823049836.

It can be written as a sum of positive squares in 4 ways, for example, as 5008644 + 633931684 = 2238^2 + 25178^2 .

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, 601 + ... + 35752.

Almost surely, 2^638940328 is an apocalyptic number.

It is an amenable number.

638940328 is an abundant number, since it is smaller than the sum of its proper divisors (658897472).

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

638940328 is a wasteful number, since it uses less digits than its factorization.

638940328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36398 (or 36368 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 43.

The square root of 638940328 is about 25277.2689980544. The cubic root of 638940328 is about 861.2979894940.

The spelling of 638940328 in words is "six hundred thirty-eight million, nine hundred forty thousand, three hundred twenty-eight".