638445308 has 6 divisors (see below), whose sum is σ = 1117279296. Its totient is φ = 319222652.

The previous prime is 638445299. The next prime is 638445329. The reversal of 638445308 is 803544836.

It is a happy number.

It is a super-2 number, since 2×638445308² = 815224822614429728, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 79805660 + ... + 79805667.

It is an arithmetic number, because the mean of its divisors is an integer number (186213216).

Almost surely, 2^638445308 is an apocalyptic number.

It is an amenable number.

638445308 is a deficient number, since it is larger than the sum of its proper divisors (478833988).

638445308 is a wasteful number, since it uses less digits than its factorization.

638445308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159611331 (or 159611329 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 41.

The square root of 638445308 is about 25267.4752992854. The cubic root of 638445308 is about 861.0755013799.

The spelling of 638445308 in words is "six hundred thirty-eight million, four hundred forty-five thousand, three hundred eight".