12666515 has 4 divisors (see below), whose sum is σ = 15199824. Its totient is φ = 10133208.

The previous prime is 12666503. The next prime is 12666517. The reversal of 12666515 is 51566621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51566621 = 23 ⋅2242027.

It is a cyclic number.

It is not a de Polignac number, because 12666515 - 2²⁰ = 11617939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12666517) 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, 1266647 + ... + 1266656.

It is an arithmetic number, because the mean of its divisors is an integer number (3799956).

Almost surely, 2^12666515 is an apocalyptic number.

12666515 is a deficient number, since it is larger than the sum of its proper divisors (2533309).

12666515 is an equidigital number, since it uses as much as digits as its factorization.

12666515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2533308.

The product of its digits is 10800, while the sum is 32.

The square root of 12666515 is about 3559.0047766194. The cubic root of 12666515 is about 233.1054248550.

The spelling of 12666515 in words is "twelve million, six hundred sixty-six thousand, five hundred fifteen".