138657688 has 32 divisors (see below), whose sum is σ = 280476000. Its totient is φ = 63883008.

The previous prime is 138657683. The next prime is 138657691. The reversal of 138657688 is 886756831.

138657688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138657683) 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, 98413 + ... + 99811.

It is an arithmetic number, because the mean of its divisors is an integer number (8764875).

Almost surely, 2^138657688 is an apocalyptic number.

It is an amenable number.

138657688 is an abundant number, since it is smaller than the sum of its proper divisors (141818312).

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

138657688 is a wasteful number, since it uses less digits than its factorization.

138657688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371 (or 2367 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 52.

The square root of 138657688 is about 11775.2999112549. The cubic root of 138657688 is about 517.5845667613.

The spelling of 138657688 in words is "one hundred thirty-eight million, six hundred fifty-seven thousand, six hundred eighty-eight".