138640841 has 2 divisors, whose sum is σ = 138640842. Its totient is φ = 138640840.

The previous prime is 138640829. The next prime is 138640867. The reversal of 138640841 is 148046831.

138640841 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., 74304400 + 64336441 = 8620^2 + 8021^2 .

It is a cyclic number.

It is not a de Polignac number, because 138640841 - 2¹⁴ = 138624457 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138640811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69320420 + 69320421.

It is an arithmetic number, because the mean of its divisors is an integer number (69320421).

Almost surely, 2^138640841 is an apocalyptic number.

It is an amenable number.

138640841 is a deficient number, since it is larger than the sum of its proper divisors (1).

138640841 is an equidigital number, since it uses as much as digits as its factorization.

138640841 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 138640841 is about 11774.5845361949. The cubic root of 138640841 is about 517.5636036242.

The spelling of 138640841 in words is "one hundred thirty-eight million, six hundred forty thousand, eight hundred forty-one".