138815688 has 32 divisors (see below), whose sum is σ = 378588960. Its totient is φ = 42065280.

The previous prime is 138815671. The next prime is 138815707. The reversal of 138815688 is 886518831.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 262645 + ... + 263172.

It is an arithmetic number, because the mean of its divisors is an integer number (11830905).

Almost surely, 2^138815688 is an apocalyptic number.

It is an amenable number.

138815688 is an abundant number, since it is smaller than the sum of its proper divisors (239773272).

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

138815688 is a wasteful number, since it uses less digits than its factorization.

138815688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525837 (or 525833 counting only the distinct ones).

The product of its digits is 368640, while the sum is 48.

The square root of 138815688 is about 11782.0069597671. The cubic root of 138815688 is about 517.7810874647.

The spelling of 138815688 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, six hundred eighty-eight".