138361691 has 16 divisors (see below), whose sum is σ = 158505984. Its totient is φ = 119645184.

The previous prime is 138361679. The next prime is 138361733. The reversal of 138361691 is 196163831.

It is a de Polignac number, because none of the positive numbers 2^k-138361691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138361621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50150 + ... + 52836.

It is an arithmetic number, because the mean of its divisors is an integer number (9906624).

Almost surely, 2^138361691 is an apocalyptic number.

138361691 is a deficient number, since it is larger than the sum of its proper divisors (20144293).

138361691 is a wasteful number, since it uses less digits than its factorization.

138361691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2950.

The product of its digits is 23328, while the sum is 38.

The square root of 138361691 is about 11762.7246418506. The cubic root of 138361691 is about 517.2160029338.

The spelling of 138361691 in words is "one hundred thirty-eight million, three hundred sixty-one thousand, six hundred ninety-one".