138156961664 has 64 divisors (see below), whose sum is σ = 281761393200. Its totient is φ = 67456696320.

The previous prime is 138156961651. The next prime is 138156961697. The reversal of 138156961664 is 466169651831.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1021664 + ... + 1148960.

Almost surely, 2^138156961664 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 138156961664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140880696600).

138156961664 is an abundant number, since it is smaller than the sum of its proper divisors (143604431536).

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

138156961664 is a wasteful number, since it uses less digits than its factorization.

138156961664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127511 (or 127499 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 56.

The spelling of 138156961664 in words is "one hundred thirty-eight billion, one hundred fifty-six million, nine hundred sixty-one thousand, six hundred sixty-four".