138523609 has 8 divisors (see below), whose sum is σ = 161300160. Its totient is φ = 116493936.

The previous prime is 138523607. The next prime is 138523613. The reversal of 138523609 is 906325831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138523609 - 2¹ = 138523607 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138523601) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 186319 + ... + 187060.

It is an arithmetic number, because the mean of its divisors is an integer number (20162520).

Almost surely, 2^138523609 is an apocalyptic number.

It is an amenable number.

138523609 is a deficient number, since it is larger than the sum of its proper divisors (22776551).

138523609 is an equidigital number, since it uses as much as digits as its factorization.

138523609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373439.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 138523609 is about 11769.6053034926. The cubic root of 138523609 is about 517.4176819130.

The spelling of 138523609 in words is "one hundred thirty-eight million, five hundred twenty-three thousand, six hundred nine".