138321215 has 4 divisors (see below), whose sum is σ = 165985464. Its totient is φ = 110656968.

The previous prime is 138321191. The next prime is 138321229. The reversal of 138321215 is 512123831.

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

It is a cyclic number.

It is not a de Polignac number, because 138321215 - 2⁶ = 138321151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13832117 + ... + 13832126.

It is an arithmetic number, because the mean of its divisors is an integer number (41496366).

Almost surely, 2^138321215 is an apocalyptic number.

138321215 is a deficient number, since it is larger than the sum of its proper divisors (27664249).

138321215 is an equidigital number, since it uses as much as digits as its factorization.

138321215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27664248.

The product of its digits is 1440, while the sum is 26.

The square root of 138321215 is about 11761.0039962581. The cubic root of 138321215 is about 517.1655629685.

The spelling of 138321215 in words is "one hundred thirty-eight million, three hundred twenty-one thousand, two hundred fifteen".