12666571 has 2 divisors, whose sum is σ = 12666572. Its totient is φ = 12666570.

The previous prime is 12666557. The next prime is 12666587. The reversal of 12666571 is 17566621.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12666571 - 2⁵ = 12666539 is a prime.

It is not a weakly prime, because it can be changed into another prime (12666371) 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 as a sum of consecutive naturals, namely, 6333285 + 6333286.

It is an arithmetic number, because the mean of its divisors is an integer number (6333286).

Almost surely, 2^12666571 is an apocalyptic number.

12666571 is a deficient number, since it is larger than the sum of its proper divisors (1).

12666571 is an equidigital number, since it uses as much as digits as its factorization.

12666571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 34.

The square root of 12666571 is about 3559.0126439787. The cubic root of 12666571 is about 233.1057683824.

It can be divided in two parts, 126665 and 71, that added together give a square (126736 = 356²).

The spelling of 12666571 in words is "twelve million, six hundred sixty-six thousand, five hundred seventy-one".