138397129 has 4 divisors (see below), whose sum is σ = 149043076. Its totient is φ = 127751184.

The previous prime is 138397111. The next prime is 138397139. The reversal of 138397129 is 921793831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69755904 + 68641225 = 8352^2 + 8285^2 .

It is a cyclic number.

It is not a de Polignac number, because 138397129 - 2⁵ = 138397097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138397109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5322954 + ... + 5322979.

It is an arithmetic number, because the mean of its divisors is an integer number (37260769).

Almost surely, 2^138397129 is an apocalyptic number.

It is an amenable number.

138397129 is a deficient number, since it is larger than the sum of its proper divisors (10645947).

138397129 is a wasteful number, since it uses less digits than its factorization.

138397129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10645946.

The product of its digits is 81648, while the sum is 43.

The square root of 138397129 is about 11764.2309140887. The cubic root of 138397129 is about 517.2601566200.

The spelling of 138397129 in words is "one hundred thirty-eight million, three hundred ninety-seven thousand, one hundred twenty-nine".