12866921 has 4 divisors (see below), whose sum is σ = 12877200. Its totient is φ = 12856644.

The previous prime is 12866911. The next prime is 12866929. The reversal of 12866921 is 12966821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12866921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12866929) 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 3 ways as a sum of consecutive naturals, for example, 2951 + ... + 5868.

It is an arithmetic number, because the mean of its divisors is an integer number (3219300).

Almost surely, 2^12866921 is an apocalyptic number.

It is an amenable number.

12866921 is a deficient number, since it is larger than the sum of its proper divisors (10279).

12866921 is an equidigital number, since it uses as much as digits as its factorization.

12866921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10278.

The product of its digits is 10368, while the sum is 35.

The square root of 12866921 is about 3587.0490657363. The cubic root of 12866921 is about 234.3283735633.

The spelling of 12866921 in words is "twelve million, eight hundred sixty-six thousand, nine hundred twenty-one".