66442723777 has 2 divisors, whose sum is σ = 66442723778. Its totient is φ = 66442723776.

The previous prime is 66442723769. The next prime is 66442723783. The reversal of 66442723777 is 77732724466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37327785616 + 29114938161 = 193204^2 + 170631^2 .

It is a cyclic number.

It is not a de Polignac number, because 66442723777 - 2³ = 66442723769 is a prime.

It is a super-2 number, since 2×66442723777² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66442723877) 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, 33221361888 + 33221361889.

It is an arithmetic number, because the mean of its divisors is an integer number (33221361889).

Almost surely, 2^66442723777 is an apocalyptic number.

It is an amenable number.

66442723777 is a deficient number, since it is larger than the sum of its proper divisors (1).

66442723777 is an equidigital number, since it uses as much as digits as its factorization.

66442723777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16595712, while the sum is 55.

The spelling of 66442723777 in words is "sixty-six billion, four hundred forty-two million, seven hundred twenty-three thousand, seven hundred seventy-seven".