138813361 has 4 divisors (see below), whose sum is σ = 138997492. Its totient is φ = 138629232.

The previous prime is 138813359. The next prime is 138813431. The reversal of 138813361 is 163318831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 163318831 = 13 ⋅12562987.

It can be written as a sum of positive squares in 2 ways, for example, as 100620961 + 38192400 = 10031^2 + 6180^2 .

It is a cyclic number.

It is not a de Polignac number, because 138813361 - 2¹ = 138813359 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138813061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90930 + ... + 92443.

It is an arithmetic number, because the mean of its divisors is an integer number (34749373).

Almost surely, 2^138813361 is an apocalyptic number.

It is an amenable number.

138813361 is a deficient number, since it is larger than the sum of its proper divisors (184131).

138813361 is an equidigital number, since it uses as much as digits as its factorization.

138813361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184130.

The product of its digits is 10368, while the sum is 34.

The square root of 138813361 is about 11781.9082070775. The cubic root of 138813361 is about 517.7781942198.

The spelling of 138813361 in words is "one hundred thirty-eight million, eight hundred thirteen thousand, three hundred sixty-one".