66800111109973 has 2 divisors, whose sum is σ = 66800111109974. Its totient is φ = 66800111109972.

The previous prime is 66800111109971. The next prime is 66800111110091. The reversal of 66800111109973 is 37990111100866.

66800111109973 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., 59484476413924 + 7315634696049 = 7712618^2 + 2704743^2 .

It is a cyclic number.

It is not a de Polignac number, because 66800111109973 - 2¹ = 66800111109971 is a prime.

It is a super-2 number, since 2×66800111109973² (a number of 28 digits) contains 22 as substring.

Together with 66800111109971, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66800111109973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66800111109971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33400055554986 + 33400055554987.

It is an arithmetic number, because the mean of its divisors is an integer number (33400055554987).

Almost surely, 2^{66800111109973} is an apocalyptic number.

It is an amenable number.

66800111109973 is a deficient number, since it is larger than the sum of its proper divisors (1).

66800111109973 is an equidigital number, since it uses as much as digits as its factorization.

66800111109973 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 489888, while the sum is 52.

The spelling of 66800111109973 in words is "sixty-six trillion, eight hundred billion, one hundred eleven million, one hundred nine thousand, nine hundred seventy-three".