138538579 has 4 divisors (see below), whose sum is σ = 138869640. Its totient is φ = 138207520.

The previous prime is 138538577. The next prime is 138538583. The reversal of 138538579 is 975835831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 975835831 = 757 ⋅1289083.

It is a cyclic number.

It is not a de Polignac number, because 138538579 - 2¹ = 138538577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138538577) 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, 164902 + ... + 165739.

It is an arithmetic number, because the mean of its divisors is an integer number (34717410).

Almost surely, 2^138538579 is an apocalyptic number.

138538579 is a deficient number, since it is larger than the sum of its proper divisors (331061).

138538579 is an equidigital number, since it uses as much as digits as its factorization.

138538579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331060.

The product of its digits is 907200, while the sum is 49.

The square root of 138538579 is about 11770.2412464656. The cubic root of 138538579 is about 517.4363200444.

The spelling of 138538579 in words is "one hundred thirty-eight million, five hundred thirty-eight thousand, five hundred seventy-nine".