12666161 has 4 divisors (see below), whose sum is σ = 12673524. Its totient is φ = 12658800.

The previous prime is 12666133. The next prime is 12666167. The reversal of 12666161 is 16166621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16166621 = 3467 ⋅4663.

It can be written as a sum of positive squares in 2 ways, for example, as 4227136 + 8439025 = 2056^2 + 2905^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12666161 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12666167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431 + ... + 5051.

It is an arithmetic number, because the mean of its divisors is an integer number (3168381).

Almost surely, 2^12666161 is an apocalyptic number.

It is an amenable number.

12666161 is a deficient number, since it is larger than the sum of its proper divisors (7363).

12666161 is an equidigital number, since it uses as much as digits as its factorization.

12666161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7362.

The product of its digits is 2592, while the sum is 29.

The square root of 12666161 is about 3558.9550432676. The cubic root of 12666161 is about 233.1032532477.

The spelling of 12666161 in words is "twelve million, six hundred sixty-six thousand, one hundred sixty-one".