638845368 has 32 divisors (see below), whose sum is σ = 1825272960. Its totient is φ = 182527200.

The previous prime is 638845331. The next prime is 638845369. The reversal of 638845368 is 863548836.

It is a self number, because there is not a number n which added to its sum of digits gives 638845368.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638845369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1901158 + ... + 1901493.

It is an arithmetic number, because the mean of its divisors is an integer number (57039780).

Almost surely, 2^638845368 is an apocalyptic number.

It is an amenable number.

638845368 is an abundant number, since it is smaller than the sum of its proper divisors (1186427592).

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

638845368 is a wasteful number, since it uses less digits than its factorization.

638845368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3802667 (or 3802663 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 51.

The square root of 638845368 is about 25275.3905607807. The cubic root of 638845368 is about 861.2553183682.

The spelling of 638845368 in words is "six hundred thirty-eight million, eight hundred forty-five thousand, three hundred sixty-eight".