138307639 has 2 divisors, whose sum is σ = 138307640. Its totient is φ = 138307638.

The previous prime is 138307633. The next prime is 138307649. The reversal of 138307639 is 936703831.

138307639 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 is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138307639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138307633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69153819 + 69153820.

It is an arithmetic number, because the mean of its divisors is an integer number (69153820).

Almost surely, 2^138307639 is an apocalyptic number.

138307639 is a deficient number, since it is larger than the sum of its proper divisors (1).

138307639 is an equidigital number, since it uses as much as digits as its factorization.

138307639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 40.

The square root of 138307639 is about 11760.4268204857. The cubic root of 138307639 is about 517.1486427648.

The spelling of 138307639 in words is "one hundred thirty-eight million, three hundred seven thousand, six hundred thirty-nine".