66045644666 has 4 divisors (see below), whose sum is σ = 99068467002. Its totient is φ = 33022822332.

The previous prime is 66045644629. The next prime is 66045644671. The reversal of 66045644666 is 66644654066.

66045644666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66644654066 = 2 ⋅33322327033.

It can be written as a sum of positive squares in only one way, i.e., 60235394041 + 5810250625 = 245429^2 + 76225^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16511411165 + ... + 16511411168.

Almost surely, 2^66045644666 is an apocalyptic number.

66045644666 is a deficient number, since it is larger than the sum of its proper divisors (33022822336).

66045644666 is a wasteful number, since it uses less digits than its factorization.

66045644666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33022822335.

The product of its (nonzero) digits is 14929920, while the sum is 53.

The spelling of 66045644666 in words is "sixty-six billion, forty-five million, six hundred forty-four thousand, six hundred sixty-six".