55332765721 has 2 divisors, whose sum is σ = 55332765722. Its totient is φ = 55332765720.

The previous prime is 55332765647. The next prime is 55332765731. The reversal of 55332765721 is 12756723355.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36010375696 + 19322390025 = 189764^2 + 139005^2 .

It is a cyclic number.

It is not a de Polignac number, because 55332765721 - 2²⁷ = 55198547993 is a prime.

It is not a weakly prime, because it can be changed into another prime (55332765731) 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, 27666382860 + 27666382861.

It is an arithmetic number, because the mean of its divisors is an integer number (27666382861).

Almost surely, 2^55332765721 is an apocalyptic number.

It is an amenable number.

55332765721 is a deficient number, since it is larger than the sum of its proper divisors (1).

55332765721 is an equidigital number, since it uses as much as digits as its factorization.

55332765721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1323000, while the sum is 46.

The spelling of 55332765721 in words is "fifty-five billion, three hundred thirty-two million, seven hundred sixty-five thousand, seven hundred twenty-one".