66322206721 has 4 divisors (see below), whose sum is σ = 69812849200. Its totient is φ = 62831564244.

The previous prime is 66322206703. The next prime is 66322206739. The reversal of 66322206721 is 12760222366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12760222366 = 2 ⋅6380111183.

It is an interprime number because it is at equal distance from previous prime (66322206703) and next prime (66322206739).

It is a cyclic number.

It is not a de Polignac number, because 66322206721 - 2¹¹ = 66322204673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66322206121) 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, 1745321211 + ... + 1745321248.

It is an arithmetic number, because the mean of its divisors is an integer number (17453212300).

Almost surely, 2^66322206721 is an apocalyptic number.

It is an amenable number.

66322206721 is a deficient number, since it is larger than the sum of its proper divisors (3490642479).

66322206721 is a wasteful number, since it uses less digits than its factorization.

66322206721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3490642478.

The product of its (nonzero) digits is 72576, while the sum is 37.

The spelling of 66322206721 in words is "sixty-six billion, three hundred twenty-two million, two hundred six thousand, seven hundred twenty-one".