138631984128 has 396 divisors, whose sum is σ = 451545666624. Its totient is φ = 40625971200.

The previous prime is 138631984109. The next prime is 138631984181. The reversal of 138631984128 is 821489136831.

138631984128 is a `hidden beast` number, since 1 + 38 + 6 + 3 + 198 + 412 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (396).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 97421625 + ... + 97423047.

Almost surely, 2^138631984128 is an apocalyptic number.

138631984128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138631984128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225772833312).

138631984128 is an abundant number, since it is smaller than the sum of its proper divisors (312913682496).

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

138631984128 is a wasteful number, since it uses less digits than its factorization.

138631984128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522 (or 1470 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 54.

It can be divided in two parts, 13863 and 1984128, that added together give a palindrome (1997991).

The spelling of 138631984128 in words is "one hundred thirty-eight billion, six hundred thirty-one million, nine hundred eighty-four thousand, one hundred twenty-eight".