138521345536 has 40 divisors (see below), whose sum is σ = 316311027120. Its totient is φ = 59366289408.

The previous prime is 138521345507. The next prime is 138521345539. The reversal of 138521345536 is 635543125831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138521345539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19321381 + ... + 19328548.

It is an arithmetic number, because the mean of its divisors is an integer number (7907775678).

Almost surely, 2^138521345536 is an apocalyptic number.

138521345536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

138521345536 is an abundant number, since it is smaller than the sum of its proper divisors (177789681584).

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

138521345536 is an frugal number, since it uses more digits than its factorization.

138521345536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38649954 (or 38649938 counting only the distinct ones).

The product of its digits is 1296000, while the sum is 46.

The spelling of 138521345536 in words is "one hundred thirty-eight billion, five hundred twenty-one million, three hundred forty-five thousand, five hundred thirty-six".