638138796 has 24 divisors (see below), whose sum is σ = 1493849280. Its totient is φ = 212018832.

The previous prime is 638138779. The next prime is 638138797. The reversal of 638138796 is 697831836.

It is a super-2 number, since 2×638138796² = 814442245920659232, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638138797) by changing a digit.

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, 82926 + ... + 90293.

It is an arithmetic number, because the mean of its divisors is an integer number (62243720).

Almost surely, 2^638138796 is an apocalyptic number.

It is an amenable number.

638138796 is an abundant number, since it is smaller than the sum of its proper divisors (855710484).

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

638138796 is a wasteful number, since it uses less digits than its factorization.

638138796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173533 (or 173531 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 51.

The square root of 638138796 is about 25261.4092243485. The cubic root of 638138796 is about 860.9376810535.

The spelling of 638138796 in words is "six hundred thirty-eight million, one hundred thirty-eight thousand, seven hundred ninety-six".