138236865 has 16 divisors (see below), whose sum is σ = 238193088. Its totient is φ = 68054976.

The previous prime is 138236849. The next prime is 138236887. The reversal of 138236865 is 568632831.

It is not a de Polignac number, because 138236865 - 2⁴ = 138236849 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 354259 + ... + 354648.

It is an arithmetic number, because the mean of its divisors is an integer number (14887068).

Almost surely, 2^138236865 is an apocalyptic number.

138236865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138236865 is a deficient number, since it is larger than the sum of its proper divisors (99956223).

138236865 is a wasteful number, since it uses less digits than its factorization.

138236865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708928.

The product of its digits is 207360, while the sum is 42.

The square root of 138236865 is about 11757.4174460210. The cubic root of 138236865 is about 517.0604169249.

The spelling of 138236865 in words is "one hundred thirty-eight million, two hundred thirty-six thousand, eight hundred sixty-five".