138500321 has 2 divisors, whose sum is σ = 138500322. Its totient is φ = 138500320.

The previous prime is 138500311. The next prime is 138500333. The reversal of 138500321 is 123005831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133726096 + 4774225 = 11564^2 + 2185^2 .

It is a cyclic number.

It is not a de Polignac number, because 138500321 - 2¹⁰ = 138499297 is a prime.

It is not a weakly prime, because it can be changed into another prime (138500311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69250160 + 69250161.

It is an arithmetic number, because the mean of its divisors is an integer number (69250161).

Almost surely, 2^138500321 is an apocalyptic number.

It is an amenable number.

138500321 is a deficient number, since it is larger than the sum of its proper divisors (1).

138500321 is an equidigital number, since it uses as much as digits as its factorization.

138500321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 138500321 is about 11768.6159339151. The cubic root of 138500321 is about 517.3886849346.

The spelling of 138500321 in words is "one hundred thirty-eight million, five hundred thousand, three hundred twenty-one".