12399221809 has 4 divisors (see below), whose sum is σ = 13353008116. Its totient is φ = 11445435504.

The previous prime is 12399221803. The next prime is 12399221831. The reversal of 12399221809 is 90812299321.

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 3174195600 + 9225026209 = 56340^2 + 96047^2 .

It is a cyclic number.

It is not a de Polignac number, because 12399221809 - 2³ = 12399221801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12399221801) 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, 476893134 + ... + 476893159.

It is an arithmetic number, because the mean of its divisors is an integer number (3338252029).

Almost surely, 2^12399221809 is an apocalyptic number.

It is an amenable number.

12399221809 is a deficient number, since it is larger than the sum of its proper divisors (953786307).

12399221809 is an equidigital number, since it uses as much as digits as its factorization.

12399221809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953786306.

The product of its (nonzero) digits is 139968, while the sum is 46.

The spelling of 12399221809 in words is "twelve billion, three hundred ninety-nine million, two hundred twenty-one thousand, eight hundred nine".