11056566721 has 2 divisors, whose sum is σ = 11056566722. Its totient is φ = 11056566720.

The previous prime is 11056566707. The next prime is 11056566761. The reversal of 11056566721 is 12766565011.

It is an a-pointer prime, because the next prime (11056566761) can be obtained adding 11056566721 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10392783025 + 663783696 = 101945^2 + 25764^2 .

It is a cyclic number.

It is not a de Polignac number, because 11056566721 - 2¹³ = 11056558529 is a prime.

It is not a weakly prime, because it can be changed into another prime (11056566761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5528283360 + 5528283361.

It is an arithmetic number, because the mean of its divisors is an integer number (5528283361).

Almost surely, 2^11056566721 is an apocalyptic number.

It is an amenable number.

11056566721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11056566721 is an equidigital number, since it uses as much as digits as its factorization.

11056566721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 40.

The spelling of 11056566721 in words is "eleven billion, fifty-six million, five hundred sixty-six thousand, seven hundred twenty-one".