138321121 has 9 divisors (see below), whose sum is σ = 146220561. Its totient is φ = 130829364.

The previous prime is 138321089. The next prime is 138321143. The reversal of 138321121 is 121123831.

It is a happy number.

The square root of 138321121 is 11761.

It is a perfect power (a square), and thus also a powerful number.

138321121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138321121 - 2⁵ = 138321089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138321092 and 138321101.

It is not an unprimeable number, because it can be changed into a prime (138321151) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 223150 + ... + 223768.

It is an arithmetic number, because the mean of its divisors is an integer number (16246729).

Almost surely, 2^138321121 is an apocalyptic number.

138321121 is the 11761-st square number.

138321121 is the 5881-st centered octagonal number.

It is an amenable number.

138321121 is a deficient number, since it is larger than the sum of its proper divisors (7899440).

138321121 is an frugal number, since it uses more digits than its factorization.

138321121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276 (or 638 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The cubic root of 138321121 is about 517.1654458171.

Adding to 138321121 its reverse (121123831), we get a palindrome (259444952).

The spelling of 138321121 in words is "one hundred thirty-eight million, three hundred twenty-one thousand, one hundred twenty-one".