666546888645666 has 48 divisors (see below), whose sum is σ = 1650498633134208. Its totient is φ = 190441786392000.

The previous prime is 666546888645661. The next prime is 666546888645691.

666546888645666 is nontrivially palindromic in base 10.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666546888645661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 185105091 + ... + 188671641.

It is an arithmetic number, because the mean of its divisors is an integer number (34385388190296).

Almost surely, 2^{666546888645666} is an apocalyptic number.

666546888645666 is an abundant number, since it is smaller than the sum of its proper divisors (983951744488542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666546888645666 is a wasteful number, since it uses less digits than its factorization.

666546888645666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5049807 (or 5049804 counting only the distinct ones).

The product of its digits is 343985356800, while the sum is 90.

The spelling of 666546888645666 in words is "six hundred sixty-six trillion, five hundred forty-six billion, eight hundred eighty-eight million, six hundred forty-five thousand, six hundred sixty-six".