12321666009 has 27 divisors (see below), whose sum is σ = 17987058453. Its totient is φ = 8128083672.

The previous prime is 12321666001. The next prime is 12321666047. The reversal of 12321666009 is 90066612321.

It is a happy number.

The square root of 12321666009 is 111003.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 12321666009 - 2³ = 12321666001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12321666001) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 54280354 + ... + 54280580.

Almost surely, 2^12321666009 is an apocalyptic number.

12321666009 is the 111003-rd square number.

12321666009 is the 55502-nd centered octagonal number.

It is an amenable number.

12321666009 is a deficient number, since it is larger than the sum of its proper divisors (5665392444).

12321666009 is an frugal number, since it uses more digits than its factorization.

12321666009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

Multiplying 12321666009 by its sum of digits (36), we get a square (443579976324 = 666018²).

It can be divided in two parts, 123216 and 66009, that added together give a square (189225 = 435²).

The spelling of 12321666009 in words is "twelve billion, three hundred twenty-one million, six hundred sixty-six thousand, nine".