638315855982 has 48 divisors (see below), whose sum is σ = 1592657269632. Its totient is φ = 180983771280.

The previous prime is 638315855971. The next prime is 638315856037. The reversal of 638315855982 is 289558513836.

638315855982 is a `hidden beast` number, since 6 + 3 + 8 + 31 + 5 + 8 + 5 + 598 + 2 = 666.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19319368 + ... + 19352379.

It is an arithmetic number, because the mean of its divisors is an integer number (33180359784).

Almost surely, 2^638315855982 is an apocalyptic number.

638315855982 is an abundant number, since it is smaller than the sum of its proper divisors (954341413650).

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

638315855982 is a wasteful number, since it uses less digits than its factorization.

638315855982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38671893 (or 38671890 counting only the distinct ones).

The product of its digits is 62208000, while the sum is 63.

The spelling of 638315855982 in words is "six hundred thirty-eight billion, three hundred fifteen million, eight hundred fifty-five thousand, nine hundred eighty-two".