66165505999 has 2 divisors, whose sum is σ = 66165506000. Its totient is φ = 66165505998.

The previous prime is 66165505949. The next prime is 66165506041. The reversal of 66165505999 is 99950556166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66165505999 - 2²¹ = 66163408847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66165505949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33082752999 + 33082753000.

It is an arithmetic number, because the mean of its divisors is an integer number (33082753000).

Almost surely, 2^66165505999 is an apocalyptic number.

66165505999 is a deficient number, since it is larger than the sum of its proper divisors (1).

66165505999 is an equidigital number, since it uses as much as digits as its factorization.

66165505999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19683000, while the sum is 61.

The spelling of 66165505999 in words is "sixty-six billion, one hundred sixty-five million, five hundred five thousand, nine hundred ninety-nine".