11725711721 has 2 divisors, whose sum is σ = 11725711722. Its totient is φ = 11725711720.

The previous prime is 11725711717. The next prime is 11725711783. The reversal of 11725711721 is 12711752711.

11725711721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11423334400 + 302377321 = 106880^2 + 17389^2 .

It is a cyclic number.

It is not a de Polignac number, because 11725711721 - 2² = 11725711717 is a prime.

It is not a weakly prime, because it can be changed into another prime (11725711321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5862855860 + 5862855861.

It is an arithmetic number, because the mean of its divisors is an integer number (5862855861).

Almost surely, 2^11725711721 is an apocalyptic number.

It is an amenable number.

11725711721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11725711721 is an equidigital number, since it uses as much as digits as its factorization.

11725711721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6860, while the sum is 35.

The spelling of 11725711721 in words is "eleven billion, seven hundred twenty-five million, seven hundred eleven thousand, seven hundred twenty-one".