138136639 has 2 divisors, whose sum is σ = 138136640. Its totient is φ = 138136638.

The previous prime is 138136591. The next prime is 138136721. The reversal of 138136639 is 936631831.

It is a weak prime.

It is an emirp because it is prime and its reverse (936631831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138136639 - 2⁹ = 138136127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138131639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69068319 + 69068320.

It is an arithmetic number, because the mean of its divisors is an integer number (69068320).

Almost surely, 2^138136639 is an apocalyptic number.

138136639 is a deficient number, since it is larger than the sum of its proper divisors (1).

138136639 is an equidigital number, since it uses as much as digits as its factorization.

138136639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 40.

The square root of 138136639 is about 11753.1544276420. The cubic root of 138136639 is about 516.9354251175.

The spelling of 138136639 in words is "one hundred thirty-eight million, one hundred thirty-six thousand, six hundred thirty-nine".