12666921 has 8 divisors (see below), whose sum is σ = 17882784. Its totient is φ = 7947840.

The previous prime is 12666919. The next prime is 12666943. The reversal of 12666921 is 12966621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12666921 - 2¹ = 12666919 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12666911) 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, 124135 + ... + 124236.

It is an arithmetic number, because the mean of its divisors is an integer number (2235348).

Almost surely, 2^12666921 is an apocalyptic number.

It is an amenable number.

12666921 is a deficient number, since it is larger than the sum of its proper divisors (5215863).

12666921 is a wasteful number, since it uses less digits than its factorization.

12666921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248391.

The product of its digits is 7776, while the sum is 33.

The square root of 12666921 is about 3559.0618145798. The cubic root of 12666921 is about 233.1079154057.

The spelling of 12666921 in words is "twelve million, six hundred sixty-six thousand, nine hundred twenty-one".