138539181500 has 24 divisors (see below), whose sum is σ = 302569573488. Its totient is φ = 55415672400.

The previous prime is 138539181499. The next prime is 138539181509. The reversal of 138539181500 is 5181935831.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138539181509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138538682 + ... + 138539681.

It is an arithmetic number, because the mean of its divisors is an integer number (12607065562).

Almost surely, 2^138539181500 is an apocalyptic number.

138539181500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138539181500 is an abundant number, since it is smaller than the sum of its proper divisors (164030391988).

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

138539181500 is a wasteful number, since it uses less digits than its factorization.

138539181500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277078382 (or 277078370 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 44.

The spelling of 138539181500 in words is "one hundred thirty-eight billion, five hundred thirty-nine million, one hundred eighty-one thousand, five hundred".