12666621 has 8 divisors (see below), whose sum is σ = 18424224. Its totient is φ = 7676720.

The previous prime is 12666607. The next prime is 12666671.

12666621 is nontrivially palindromic in base 10.

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 12666621 - 2⁶ = 12666557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12666601) 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, 191886 + ... + 191951.

It is an arithmetic number, because the mean of its divisors is an integer number (2303028).

Almost surely, 2^12666621 is an apocalyptic number.

12666621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12666621 is a deficient number, since it is larger than the sum of its proper divisors (5757603).

12666621 is a wasteful number, since it uses less digits than its factorization.

12666621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383851.

The product of its digits is 5184, while the sum is 30.

The square root of 12666621 is about 3559.0196683918. The cubic root of 12666621 is about 233.1060751024.

It can be divided in two parts, 1266 and 6621, that added together give a palindrome (7887).

The spelling of 12666621 in words is "twelve million, six hundred sixty-six thousand, six hundred twenty-one".