638843212572 has 12 divisors (see below), whose sum is σ = 1490634162696. Its totient is φ = 212947737520.

The previous prime is 638843212537. The next prime is 638843212583. The reversal of 638843212572 is 275212348836.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26618467179 + ... + 26618467202.

It is an arithmetic number, because the mean of its divisors is an integer number (124219513558).

Almost surely, 2^638843212572 is an apocalyptic number.

It is an amenable number.

638843212572 is an abundant number, since it is smaller than the sum of its proper divisors (851790950124).

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

638843212572 is a wasteful number, since it uses less digits than its factorization.

638843212572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53236934388 (or 53236934386 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 51.

The spelling of 638843212572 in words is "six hundred thirty-eight billion, eight hundred forty-three million, two hundred twelve thousand, five hundred seventy-two".