12138817 has 4 divisors (see below), whose sum is σ = 12337876. Its totient is φ = 11939760.

The previous prime is 12138811. The next prime is 12138821. The reversal of 12138817 is 71883121.

It is a happy number.

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 6922161 + 5216656 = 2631^2 + 2284^2 .

It is a cyclic number.

It is not a de Polignac number, because 12138817 - 2³ = 12138809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12138811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99438 + ... + 99559.

It is an arithmetic number, because the mean of its divisors is an integer number (3084469).

Almost surely, 2^12138817 is an apocalyptic number.

It is an amenable number.

12138817 is a deficient number, since it is larger than the sum of its proper divisors (199059).

12138817 is an equidigital number, since it uses as much as digits as its factorization.

12138817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199058.

The product of its digits is 2688, while the sum is 31.

The square root of 12138817 is about 3484.0805099768. The cubic root of 12138817 is about 229.8222760644.

The spelling of 12138817 in words is "twelve million, one hundred thirty-eight thousand, eight hundred seventeen".