66605615999 has 6 divisors (see below), whose sum is σ = 72123241176. Its totient is φ = 61482106920.

The previous prime is 66605615939. The next prime is 66605616013. The reversal of 66605615999 is 99951650666.

It is not a de Polignac number, because 66605615999 - 2¹² = 66605611903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66605615929) 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 in 5 ways as a sum of consecutive naturals, for example, 197057867 + ... + 197058204.

It is an arithmetic number, because the mean of its divisors is an integer number (12020540196).

Almost surely, 2^66605615999 is an apocalyptic number.

66605615999 is a deficient number, since it is larger than the sum of its proper divisors (5517625177).

66605615999 is a wasteful number, since it uses less digits than its factorization.

66605615999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394116097 (or 394116084 counting only the distinct ones).

The product of its (nonzero) digits is 23619600, while the sum is 62.

The spelling of 66605615999 in words is "sixty-six billion, six hundred five million, six hundred fifteen thousand, nine hundred ninety-nine".