138665385 has 32 divisors (see below), whose sum is σ = 255024000. Its totient is φ = 71402688.

The previous prime is 138665377. The next prime is 138665407. The reversal of 138665385 is 583566831.

138665385 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138665385 - 2³ = 138665377 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 138665385.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13795 + ... + 21624.

It is an arithmetic number, because the mean of its divisors is an integer number (7969500).

Almost surely, 2^138665385 is an apocalyptic number.

138665385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138665385 is a deficient number, since it is larger than the sum of its proper divisors (116358615).

138665385 is a wasteful number, since it uses less digits than its factorization.

138665385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35462 (or 35456 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 138665385 is about 11775.6267349131. The cubic root of 138665385 is about 517.5941437629.

The spelling of 138665385 in words is "one hundred thirty-eight million, six hundred sixty-five thousand, three hundred eighty-five".