138738649968 has 60 divisors (see below), whose sum is σ = 405157081680. Its totient is φ = 44235510528.

The previous prime is 138738649967. The next prime is 138738649999. The reversal of 138738649968 is 869946837831.

138738649968 is a `hidden beast` number, since 1 + 3 + 8 + 73 + 8 + 6 + 499 + 68 = 666.

138738649968 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (72) 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 (72).

It is a junction number, because it is equal to n+sod(n) for n = 138738649896 and 138738649905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138738649967) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 20941533 + ... + 20948156.

It is an arithmetic number, because the mean of its divisors is an integer number (6752618028).

Almost surely, 2^138738649968 is an apocalyptic number.

138738649968 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138738649968 is an abundant number, since it is smaller than the sum of its proper divisors (266418431712).

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

138738649968 is a wasteful number, since it uses less digits than its factorization.

138738649968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41889726 (or 41889717 counting only the distinct ones).

The product of its digits is 376233984, while the sum is 72.

The spelling of 138738649968 in words is "one hundred thirty-eight billion, seven hundred thirty-eight million, six hundred forty-nine thousand, nine hundred sixty-eight".