66066061997 has 8 divisors (see below), whose sum is σ = 75333247416. Its totient is φ = 57396759552.

The previous prime is 66066061987. The next prime is 66066062053. The reversal of 66066061997 is 79916066066.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1924927876 + 64141134121 = 43874^2 + 253261^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66066061997 - 2¹² = 66066057901 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 (66066061987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149470508 + ... + 149470949.

It is an arithmetic number, because the mean of its divisors is an integer number (9416655927).

Almost surely, 2^66066061997 is an apocalyptic number.

It is an amenable number.

66066061997 is a deficient number, since it is larger than the sum of its proper divisors (9267185419).

66066061997 is a wasteful number, since it uses less digits than its factorization.

66066061997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298941487.

The product of its (nonzero) digits is 4408992, while the sum is 56.

The spelling of 66066061997 in words is "sixty-six billion, sixty-six million, sixty-one thousand, nine hundred ninety-seven".