638349865024 has 21 divisors (see below), whose sum is σ = 1266738197151. Its totient is φ = 319171736640.

The previous prime is 638349865009. The next prime is 638349865033. The reversal of 638349865024 is 420568943836.

The square root of 638349865024 is 798968.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638349865024.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 6341809 + ... + 6441679.

It is an arithmetic number, because the mean of its divisors is an integer number (60320866531).

Almost surely, 2^638349865024 is an apocalyptic number.

638349865024 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

638349865024 is the 798968-th square number.

It is an amenable number.

638349865024 is a deficient number, since it is larger than the sum of its proper divisors (628388332127).

638349865024 is an frugal number, since it uses more digits than its factorization.

638349865024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199754 (or 99873 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 58.

The spelling of 638349865024 in words is "six hundred thirty-eight billion, three hundred forty-nine million, eight hundred sixty-five thousand, twenty-four".