12228711661 has 4 divisors (see below), whose sum is σ = 12229249500. Its totient is φ = 12228173824.

The previous prime is 12228711647. The next prime is 12228711667. The reversal of 12228711661 is 16611782221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16611782221 = 25163 ⋅660167.

It can be written as a sum of positive squares in 2 ways, for example, as 4122410436 + 8106301225 = 64206^2 + 90035^2 .

It is a cyclic number.

It is not a de Polignac number, because 12228711661 - 2⁹ = 12228711149 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12228711661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12228711667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233236 + ... + 280813.

It is an arithmetic number, because the mean of its divisors is an integer number (3057312375).

Almost surely, 2^12228711661 is an apocalyptic number.

It is an amenable number.

12228711661 is a deficient number, since it is larger than the sum of its proper divisors (537839).

12228711661 is an equidigital number, since it uses as much as digits as its factorization.

12228711661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537838.

The product of its digits is 16128, while the sum is 37.

The spelling of 12228711661 in words is "twelve billion, two hundred twenty-eight million, seven hundred eleven thousand, six hundred sixty-one".