138549437 has 4 divisors (see below), whose sum is σ = 149207100. Its totient is φ = 127891776.

The previous prime is 138549419. The next prime is 138549449. The reversal of 138549437 is 734945831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 734945831 = 59 ⋅12456709.

It can be written as a sum of positive squares in 2 ways, for example, as 67551961 + 70997476 = 8219^2 + 8426^2 .

It is a cyclic number.

It is not a de Polignac number, because 138549437 - 2⁸ = 138549181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138549457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5328812 + ... + 5328837.

It is an arithmetic number, because the mean of its divisors is an integer number (37301775).

Almost surely, 2^138549437 is an apocalyptic number.

It is an amenable number.

138549437 is a deficient number, since it is larger than the sum of its proper divisors (10657663).

138549437 is a wasteful number, since it uses less digits than its factorization.

138549437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10657662.

The product of its digits is 362880, while the sum is 44.

The square root of 138549437 is about 11770.7024854084. The cubic root of 138549437 is about 517.4498377635.

The spelling of 138549437 in words is "one hundred thirty-eight million, five hundred forty-nine thousand, four hundred thirty-seven".