66205856719 has 2 divisors, whose sum is σ = 66205856720. Its totient is φ = 66205856718.

The previous prime is 66205856641. The next prime is 66205856779. The reversal of 66205856719 is 91765850266.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66205856719 - 2⁹ = 66205856207 is a prime.

It is a super-2 number, since 2×66205856719² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66205856719.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66205856779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33102928359 + 33102928360.

It is an arithmetic number, because the mean of its divisors is an integer number (33102928360).

Almost surely, 2^66205856719 is an apocalyptic number.

66205856719 is a deficient number, since it is larger than the sum of its proper divisors (1).

66205856719 is an equidigital number, since it uses as much as digits as its factorization.

66205856719 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5443200, while the sum is 55.

The spelling of 66205856719 in words is "sixty-six billion, two hundred five million, eight hundred fifty-six thousand, seven hundred nineteen".