638448985512 has 576 divisors, whose sum is σ = 2012702515200. Its totient is φ = 182333099520.

The previous prime is 638448985457. The next prime is 638448985631. The reversal of 638448985512 is 215589844836.

638448985512 is a `hidden beast` number, since 6 + 38 + 4 + 4 + 8 + 9 + 85 + 512 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 638448985512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1481319937 + ... + 1481320367.

It is an arithmetic number, because the mean of its divisors is an integer number (3494275200).

Almost surely, 2^638448985512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638448985512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1006351257600).

638448985512 is an abundant number, since it is smaller than the sum of its proper divisors (1374253529688).

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

638448985512 is a wasteful number, since it uses less digits than its factorization.

638448985512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638 (or 618 counting only the distinct ones).

The product of its digits is 66355200, while the sum is 63.

The spelling of 638448985512 in words is "six hundred thirty-eight billion, four hundred forty-eight million, nine hundred eighty-five thousand, five hundred twelve".