138690647 has 2 divisors, whose sum is σ = 138690648. Its totient is φ = 138690646.

The previous prime is 138690623. The next prime is 138690653. The reversal of 138690647 is 746096831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138690647 - 2¹⁰ = 138689623 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 138690598 and 138690607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138690677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69345323 + 69345324.

It is an arithmetic number, because the mean of its divisors is an integer number (69345324).

Almost surely, 2^138690647 is an apocalyptic number.

138690647 is a deficient number, since it is larger than the sum of its proper divisors (1).

138690647 is an equidigital number, since it uses as much as digits as its factorization.

138690647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 138690647 is about 11776.6993253628. The cubic root of 138690647 is about 517.6255735469.

The spelling of 138690647 in words is "one hundred thirty-eight million, six hundred ninety thousand, six hundred forty-seven".