638795140 has 12 divisors (see below), whose sum is σ = 1341469836. Its totient is φ = 255518048.

The previous prime is 638795099. The next prime is 638795159. The reversal of 638795140 is 41597836.

It can be written as a sum of positive squares in 2 ways, for example, as 180150084 + 458645056 = 13422^2 + 21416^2 .

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 3 ways as a sum of consecutive naturals, for example, 15969859 + ... + 15969898.

It is an arithmetic number, because the mean of its divisors is an integer number (111789153).

Almost surely, 2^638795140 is an apocalyptic number.

It is an amenable number.

638795140 is an abundant number, since it is smaller than the sum of its proper divisors (702674696).

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

638795140 is a wasteful number, since it uses less digits than its factorization.

638795140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31939766 (or 31939764 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 638795140 is about 25274.3969265342. The cubic root of 638795140 is about 861.2327462571.

The spelling of 638795140 in words is "six hundred thirty-eight million, seven hundred ninety-five thousand, one hundred forty".