138607321 has 2 divisors, whose sum is σ = 138607322. Its totient is φ = 138607320.

The previous prime is 138607319. The next prime is 138607351. The reversal of 138607321 is 123706831.

138607321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84437721 + 54169600 = 9189^2 + 7360^2 .

It is an emirp because it is prime and its reverse (123706831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138607321 - 2¹ = 138607319 is a prime.

Together with 138607319, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138607351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69303660 + 69303661.

It is an arithmetic number, because the mean of its divisors is an integer number (69303661).

Almost surely, 2^138607321 is an apocalyptic number.

It is an amenable number.

138607321 is a deficient number, since it is larger than the sum of its proper divisors (1).

138607321 is an equidigital number, since it uses as much as digits as its factorization.

138607321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 138607321 is about 11773.1610453608. The cubic root of 138607321 is about 517.5218888110.

The spelling of 138607321 in words is "one hundred thirty-eight million, six hundred seven thousand, three hundred twenty-one".