66784673819 has 2 divisors, whose sum is σ = 66784673820. Its totient is φ = 66784673818.

The previous prime is 66784673801. The next prime is 66784673831. The reversal of 66784673819 is 91837648766.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66784673819 is a prime.

It is a super-2 number, since 2×66784673819² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66784673899) 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, 33392336909 + 33392336910.

It is an arithmetic number, because the mean of its divisors is an integer number (33392336910).

Almost surely, 2^66784673819 is an apocalyptic number.

66784673819 is a deficient number, since it is larger than the sum of its proper divisors (1).

66784673819 is an equidigital number, since it uses as much as digits as its factorization.

66784673819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73156608, while the sum is 65.

The spelling of 66784673819 in words is "sixty-six billion, seven hundred eighty-four million, six hundred seventy-three thousand, eight hundred nineteen".