138938729 has 2 divisors, whose sum is σ = 138938730. Its totient is φ = 138938728.

The previous prime is 138938713. The next prime is 138938753. The reversal of 138938729 is 927839831.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89208025 + 49730704 = 9445^2 + 7052^2 .

It is a cyclic number.

It is not a de Polignac number, because 138938729 - 2⁴ = 138938713 is a prime.

It is a super-2 number, since 2×138938729² = 38607940832270882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138938029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69469364 + 69469365.

It is an arithmetic number, because the mean of its divisors is an integer number (69469365).

Almost surely, 2^138938729 is an apocalyptic number.

It is an amenable number.

138938729 is a deficient number, since it is larger than the sum of its proper divisors (1).

138938729 is an equidigital number, since it uses as much as digits as its factorization.

138938729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 50.

The square root of 138938729 is about 11787.2273669426. The cubic root of 138938729 is about 517.9340228427.

It can be divided in two parts, 13893 and 8729, that added together give a palindrome (22622).

The spelling of 138938729 in words is "one hundred thirty-eight million, nine hundred thirty-eight thousand, seven hundred twenty-nine".