138394865 has 24 divisors (see below), whose sum is σ = 196094592. Its totient is φ = 93471840.

The previous prime is 138394849. The next prime is 138394871. The reversal of 138394865 is 568493831.

It is not a de Polignac number, because 138394865 - 2⁴ = 138394849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 12200 + ... + 20630.

It is an arithmetic number, because the mean of its divisors is an integer number (8170608).

Almost surely, 2^138394865 is an apocalyptic number.

It is an amenable number.

138394865 is a deficient number, since it is larger than the sum of its proper divisors (57699727).

138394865 is an equidigital number, since it uses as much as digits as its factorization.

138394865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8517 (or 8510 counting only the distinct ones).

The product of its digits is 622080, while the sum is 47.

The square root of 138394865 is about 11764.1346898104. The cubic root of 138394865 is about 517.2573360332.

The spelling of 138394865 in words is "one hundred thirty-eight million, three hundred ninety-four thousand, eight hundred sixty-five".