138657660 has 48 divisors (see below), whose sum is σ = 393572256. Its totient is φ = 36467712.

The previous prime is 138657653. The next prime is 138657677. The reversal of 138657660 is 66756831.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11449 + ... + 20208.

It is an arithmetic number, because the mean of its divisors is an integer number (8199422).

Almost surely, 2^138657660 is an apocalyptic number.

138657660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138657660 is an abundant number, since it is smaller than the sum of its proper divisors (254914596).

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

138657660 is a wasteful number, since it uses less digits than its factorization.

138657660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31742 (or 31740 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 42.

The square root of 138657660 is about 11775.2987223255. The cubic root of 138657660 is about 517.5845319216.

The spelling of 138657660 in words is "one hundred thirty-eight million, six hundred fifty-seven thousand, six hundred sixty".