11664554221 has 4 divisors (see below), whose sum is σ = 11670731100. Its totient is φ = 11658377344.

The previous prime is 11664554219. The next prime is 11664554227. The reversal of 11664554221 is 12245546611.

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 8485173225 + 3179380996 = 92115^2 + 56386^2 .

It is a cyclic number.

It is not a de Polignac number, because 11664554221 - 2¹ = 11664554219 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 (11664554227) 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, 3085606 + ... + 3089383.

It is an arithmetic number, because the mean of its divisors is an integer number (2917682775).

Almost surely, 2^11664554221 is an apocalyptic number.

It is an amenable number.

11664554221 is a deficient number, since it is larger than the sum of its proper divisors (6176879).

11664554221 is an equidigital number, since it uses as much as digits as its factorization.

11664554221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6176878.

The product of its digits is 57600, while the sum is 37.

The spelling of 11664554221 in words is "eleven billion, six hundred sixty-four million, five hundred fifty-four thousand, two hundred twenty-one".