638378455284 has 144 divisors (see below), whose sum is σ = 1710605265600. Its totient is φ = 205753939776.

The previous prime is 638378455259. The next prime is 638378455289. The reversal of 638378455284 is 482554873836.

638378455284 is a `hidden beast` number, since 6 + 3 + 8 + 3 + 78 + 4 + 552 + 8 + 4 = 666.

Its product of digits (154828800) is a multiple of the sum of its prime divisors (1280).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638378455289) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 568457547 + ... + 568458669.

Almost surely, 2^638378455284 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 638378455284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (855302632800).

638378455284 is an abundant number, since it is smaller than the sum of its proper divisors (1072226810316).

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

638378455284 is a wasteful number, since it uses less digits than its factorization.

638378455284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2411 (or 1280 counting only the distinct ones).

The product of its digits is 154828800, while the sum is 63.

The spelling of 638378455284 in words is "six hundred thirty-eight billion, three hundred seventy-eight million, four hundred fifty-five thousand, two hundred eighty-four".