138389705 has 4 divisors (see below), whose sum is σ = 166067652. Its totient is φ = 110711760.

The previous prime is 138389701. The next prime is 138389717. The reversal of 138389705 is 507983831.

It is a happy number.

138389705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 507983831 = 601 ⋅845231.

It can be written as a sum of positive squares in 2 ways, for example, as 15335056 + 123054649 = 3916^2 + 11093^2 .

It is not a de Polignac number, because 138389705 - 2² = 138389701 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (138389701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13838966 + ... + 13838975.

It is an arithmetic number, because the mean of its divisors is an integer number (41516913).

Almost surely, 2^138389705 is an apocalyptic number.

It is an amenable number.

138389705 is a deficient number, since it is larger than the sum of its proper divisors (27677947).

138389705 is an equidigital number, since it uses as much as digits as its factorization.

138389705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27677946.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 138389705 is about 11763.9153771183. The cubic root of 138389705 is about 517.2509073721.

The spelling of 138389705 in words is "one hundred thirty-eight million, three hundred eighty-nine thousand, seven hundred five".