138305165 has 4 divisors (see below), whose sum is σ = 165966204. Its totient is φ = 110644128.

The previous prime is 138305131. The next prime is 138305171. The reversal of 138305165 is 561503831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 561503831 = 7 ⋅80214833.

It can be written as a sum of positive squares in 2 ways, for example, as 92891044 + 45414121 = 9638^2 + 6739^2 .

It is a cyclic number.

It is not a de Polignac number, because 138305165 - 2¹⁴ = 138288781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13830512 + ... + 13830521.

It is an arithmetic number, because the mean of its divisors is an integer number (41491551).

Almost surely, 2^138305165 is an apocalyptic number.

It is an amenable number.

138305165 is a deficient number, since it is larger than the sum of its proper divisors (27661039).

138305165 is an equidigital number, since it uses as much as digits as its factorization.

138305165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27661038.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 138305165 is about 11760.3216367581. The cubic root of 138305165 is about 517.1455592201.

Adding to 138305165 its reverse (561503831), we get a palindrome (699808996).

The spelling of 138305165 in words is "one hundred thirty-eight million, three hundred five thousand, one hundred sixty-five".