12666647 has 8 divisors (see below), whose sum is σ = 14772000. Its totient is φ = 10856832.

The previous prime is 12666607. The next prime is 12666671. The reversal of 12666647 is 74666621.

It is a de Polignac number, because none of the positive numbers 2^k-12666647 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12666647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12666607) 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 7 ways as a sum of consecutive naturals, for example, 18122 + ... + 18807.

It is an arithmetic number, because the mean of its divisors is an integer number (1846500).

Almost surely, 2^12666647 is an apocalyptic number.

12666647 is a deficient number, since it is larger than the sum of its proper divisors (2105353).

12666647 is an frugal number, since it uses more digits than its factorization.

12666647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36950 (or 36936 counting only the distinct ones).

The product of its digits is 72576, while the sum is 38.

The square root of 12666647 is about 3559.0233210812. The cubic root of 12666647 is about 233.1062345965.

The spelling of 12666647 in words is "twelve million, six hundred sixty-six thousand, six hundred forty-seven".