12665666 has 16 divisors (see below), whose sum is σ = 21537600. Its totient is φ = 5537808.

The previous prime is 12665659. The next prime is 12665669. The reversal of 12665666 is 66656621.

It is a super-4 number, since 4×12665666⁴ (a number of 30 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is not an unprimeable number, because it can be changed into a prime (12665669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12326 + ... + 13313.

It is an arithmetic number, because the mean of its divisors is an integer number (1346100).

Almost surely, 2^12665666 is an apocalyptic number.

12665666 is a deficient number, since it is larger than the sum of its proper divisors (8871934).

12665666 is a wasteful number, since it uses less digits than its factorization.

12665666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25673.

The product of its digits is 77760, while the sum is 38.

The square root of 12665666 is about 3558.8854997035. The cubic root of 12665666 is about 233.1002166104.

It can be divided in two parts, 12665 and 666, that added together give a palindrome (13331).

The spelling of 12665666 in words is "twelve million, six hundred sixty-five thousand, six hundred sixty-six".