138530879 has 4 divisors (see below), whose sum is σ = 140878920. Its totient is φ = 136182840.

The previous prime is 138530857. The next prime is 138530891. The reversal of 138530879 is 978035831.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138530879 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 (138530809) 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, 1173932 + ... + 1174049.

It is an arithmetic number, because the mean of its divisors is an integer number (35219730).

Almost surely, 2^138530879 is an apocalyptic number.

138530879 is a deficient number, since it is larger than the sum of its proper divisors (2348041).

138530879 is an equidigital number, since it uses as much as digits as its factorization.

138530879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2348040.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 138530879 is about 11769.9141458211. The cubic root of 138530879 is about 517.4267334645.

The spelling of 138530879 in words is "one hundred thirty-eight million, five hundred thirty thousand, eight hundred seventy-nine".