12666819722 has 4 divisors (see below), whose sum is σ = 19000229586. Its totient is φ = 6333409860.

The previous prime is 12666819719. The next prime is 12666819727. The reversal of 12666819722 is 22791866621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22791866621 = 89 ⋅256088389.

It can be written as a sum of positive squares in only one way, i.e., 12214449361 + 452370361 = 110519^2 + 21269^2 .

It is not an unprimeable number, because it can be changed into a prime (12666819727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3166704929 + ... + 3166704932.

Almost surely, 2^12666819722 is an apocalyptic number.

12666819722 is a deficient number, since it is larger than the sum of its proper divisors (6333409864).

12666819722 is an equidigital number, since it uses as much as digits as its factorization.

12666819722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6333409863.

The product of its digits is 870912, while the sum is 50.

The spelling of 12666819722 in words is "twelve billion, six hundred sixty-six million, eight hundred nineteen thousand, seven hundred twenty-two".