138378818196 has 18 divisors (see below), whose sum is σ = 349790901642. Its totient is φ = 46126272720.

The previous prime is 138378818161. The next prime is 138378818197. The reversal of 138378818196 is 691818873831.

138378818196 is a `hidden beast` number, since 1 + 383 + 78 + 8 + 181 + 9 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 121417402500 + 16961415696 = 348450^2 + 130236^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138378818197) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1921927995 + ... + 1921928066.

It is an arithmetic number, because the mean of its divisors is an integer number (19432827869).

Almost surely, 2^138378818196 is an apocalyptic number.

It is an amenable number.

138378818196 is an abundant number, since it is smaller than the sum of its proper divisors (211412083446).

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

138378818196 is a wasteful number, since it uses less digits than its factorization.

138378818196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3843856071 (or 3843856066 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 63.

The spelling of 138378818196 in words is "one hundred thirty-eight billion, three hundred seventy-eight million, eight hundred eighteen thousand, one hundred ninety-six".