638587047834 has 56 divisors (see below), whose sum is σ = 1437214384692. Its totient is φ = 212706648000.

The previous prime is 638587047829. The next prime is 638587047851. The reversal of 638587047834 is 438740785836.

638587047834 is a `hidden beast` number, since 6 + 3 + 8 + 587 + 0 + 47 + 8 + 3 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 633939217209 + 4647830625 = 796203^2 + 68175^2 .

It is a super-2 number, since 2×638587047834² (a number of 24 digits) contains 22 as substring.

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 27 ways as a sum of consecutive naturals, for example, 1842334 + ... + 2161334.

Almost surely, 2^638587047834 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638587047834, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (718607192346).

638587047834 is an abundant number, since it is smaller than the sum of its proper divisors (798627336858).

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

638587047834 is a wasteful number, since it uses less digits than its factorization.

638587047834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320394 (or 320379 counting only the distinct ones).

The product of its (nonzero) digits is 108380160, while the sum is 63.

The spelling of 638587047834 in words is "six hundred thirty-eight billion, five hundred eighty-seven million, forty-seven thousand, eight hundred thirty-four".