138608591 has 16 divisors (see below), whose sum is σ = 160272000. Its totient is φ = 118548000.

The previous prime is 138608579. The next prime is 138608669. The reversal of 138608591 is 195806831.

It is a cyclic number.

It is not a de Polignac number, because 138608591 - 2¹⁸ = 138346447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138608501) 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, 28916 + ... + 33366.

It is an arithmetic number, because the mean of its divisors is an integer number (10017000).

Almost surely, 2^138608591 is an apocalyptic number.

138608591 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138608591 is a deficient number, since it is larger than the sum of its proper divisors (21663409).

138608591 is a wasteful number, since it uses less digits than its factorization.

138608591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4630.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 138608591 is about 11773.2149814738. The cubic root of 138608591 is about 517.5234694172.

The spelling of 138608591 in words is "one hundred thirty-eight million, six hundred eight thousand, five hundred ninety-one".