12666181 has 4 divisors (see below), whose sum is σ = 13817664. Its totient is φ = 11514700.

The previous prime is 12666167. The next prime is 12666191. The reversal of 12666181 is 18166621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18166621 = 11 ⋅1651511.

It is a cyclic number.

It is not a de Polignac number, because 12666181 - 2⁹ = 12665669 is a prime.

It is a super-2 number, since 2×12666181² = 320864282249522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12666131) 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, 575725 + ... + 575746.

It is an arithmetic number, because the mean of its divisors is an integer number (3454416).

Almost surely, 2^12666181 is an apocalyptic number.

12666181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12666181 is a deficient number, since it is larger than the sum of its proper divisors (1151483).

12666181 is a wasteful number, since it uses less digits than its factorization.

12666181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1151482.

The product of its digits is 3456, while the sum is 31.

The square root of 12666181 is about 3558.9578530800. The cubic root of 12666181 is about 233.1033759385.

It can be divided in two parts, 1266 and 6181, that added together give a palindrome (7447).

The spelling of 12666181 in words is "twelve million, six hundred sixty-six thousand, one hundred eighty-one".