66549336719 has 2 divisors, whose sum is σ = 66549336720. Its totient is φ = 66549336718.

The previous prime is 66549336709. The next prime is 66549336767. The reversal of 66549336719 is 91763394566.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66549336719 is a prime.

It is a super-2 number, since 2×66549336719² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66549336709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33274668359 + 33274668360.

It is an arithmetic number, because the mean of its divisors is an integer number (33274668360).

Almost surely, 2^66549336719 is an apocalyptic number.

66549336719 is a deficient number, since it is larger than the sum of its proper divisors (1).

66549336719 is an equidigital number, since it uses as much as digits as its factorization.

66549336719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22044960, while the sum is 59.

The spelling of 66549336719 in words is "sixty-six billion, five hundred forty-nine million, three hundred thirty-six thousand, seven hundred nineteen".