138942407 has 2 divisors, whose sum is σ = 138942408. Its totient is φ = 138942406.

The previous prime is 138942373. The next prime is 138942413. The reversal of 138942407 is 704249831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138942407 - 2¹⁸ = 138680263 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138942467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69471203 + 69471204.

It is an arithmetic number, because the mean of its divisors is an integer number (69471204).

Almost surely, 2^138942407 is an apocalyptic number.

138942407 is a deficient number, since it is larger than the sum of its proper divisors (1).

138942407 is an equidigital number, since it uses as much as digits as its factorization.

138942407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 138942407 is about 11787.3833822439. The cubic root of 138942407 is about 517.9385930696.

The spelling of 138942407 in words is "one hundred thirty-eight million, nine hundred forty-two thousand, four hundred seven".