12666505 has 4 divisors (see below), whose sum is σ = 15199812. Its totient is φ = 10133200.

The previous prime is 12666503. The next prime is 12666517. The reversal of 12666505 is 50566621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2064969 + 10601536 = 1437^2 + 3256^2 .

It is not a de Polignac number, because 12666505 - 2¹ = 12666503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12666503) 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, 1266646 + ... + 1266655.

It is an arithmetic number, because the mean of its divisors is an integer number (3799953).

Almost surely, 2^12666505 is an apocalyptic number.

It is an amenable number.

12666505 is a deficient number, since it is larger than the sum of its proper divisors (2533307).

12666505 is an equidigital number, since it uses as much as digits as its factorization.

12666505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2533306.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 12666505 is about 3559.0033717320. The cubic root of 12666505 is about 233.1053635107.

The spelling of 12666505 in words is "twelve million, six hundred sixty-six thousand, five hundred five".