12138605 has 4 divisors (see below), whose sum is σ = 14566332. Its totient is φ = 9710880.

The previous prime is 12138593. The next prime is 12138613. The reversal of 12138605 is 50683121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7107556 + 5031049 = 2666^2 + 2243^2 .

It is not a de Polignac number, because 12138605 - 2⁴ = 12138589 is a prime.

It is a Duffinian number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 1213856 + ... + 1213865.

It is an arithmetic number, because the mean of its divisors is an integer number (3641583).

Almost surely, 2^12138605 is an apocalyptic number.

It is an amenable number.

12138605 is a deficient number, since it is larger than the sum of its proper divisors (2427727).

12138605 is an equidigital number, since it uses as much as digits as its factorization.

12138605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2427726.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 12138605 is about 3484.0500857479. The cubic root of 12138605 is about 229.8209381359.

The spelling of 12138605 in words is "twelve million, one hundred thirty-eight thousand, six hundred five".