138389549 has 4 divisors (see below), whose sum is σ = 142853760. Its totient is φ = 133925340.

The previous prime is 138389527. The next prime is 138389557. The reversal of 138389549 is 945983831.

138389549 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 a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 945983831 = 13 ⋅72767987.

It is a cyclic number.

It is not a de Polignac number, because 138389549 - 2¹⁶ = 138324013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138389497 and 138389506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138389569) 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, 2232059 + ... + 2232120.

It is an arithmetic number, because the mean of its divisors is an integer number (35713440).

Almost surely, 2^138389549 is an apocalyptic number.

It is an amenable number.

138389549 is a deficient number, since it is larger than the sum of its proper divisors (4464211).

138389549 is an equidigital number, since it uses as much as digits as its factorization.

138389549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4464210.

The product of its digits is 933120, while the sum is 50.

The square root of 138389549 is about 11763.9087466709. The cubic root of 138389549 is about 517.2507130148.

The spelling of 138389549 in words is "one hundred thirty-eight million, three hundred eighty-nine thousand, five hundred forty-nine".