12221266399 has 4 divisors (see below), whose sum is σ = 12223365280. Its totient is φ = 12219167520.

The previous prime is 12221266397. The next prime is 12221266403. The reversal of 12221266399 is 99366212221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12221266399 - 2¹ = 12221266397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221266397) 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, 1040682 + ... + 1052359.

It is an arithmetic number, because the mean of its divisors is an integer number (3055841320).

Almost surely, 2^12221266399 is an apocalyptic number.

12221266399 is a deficient number, since it is larger than the sum of its proper divisors (2098881).

12221266399 is an equidigital number, since it uses as much as digits as its factorization.

12221266399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2098880.

The product of its digits is 139968, while the sum is 43.

It can be divided in two parts, 1222 and 1266399, that added together give a palindrome (1267621).

The spelling of 12221266399 in words is "twelve billion, two hundred twenty-one million, two hundred sixty-six thousand, three hundred ninety-nine".