138109243 has 2 divisors, whose sum is σ = 138109244. Its totient is φ = 138109242.

The previous prime is 138109193. The next prime is 138109253. The reversal of 138109243 is 342901831.

138109243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138109243 is a prime.

It is not a weakly prime, because it can be changed into another prime (138109253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69054621 + 69054622.

It is an arithmetic number, because the mean of its divisors is an integer number (69054622).

Almost surely, 2^138109243 is an apocalyptic number.

138109243 is a deficient number, since it is larger than the sum of its proper divisors (1).

138109243 is an equidigital number, since it uses as much as digits as its factorization.

138109243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 138109243 is about 11751.9888955019. The cubic root of 138109243 is about 516.9012490550.

The spelling of 138109243 in words is "one hundred thirty-eight million, one hundred nine thousand, two hundred forty-three".