666216447045 has 16 divisors (see below), whose sum is σ = 1075908432960. Its totient is φ = 351994732544.

The previous prime is 666216447041. The next prime is 666216447053. The reversal of 666216447045 is 540744612666.

It is a cyclic number.

It is not a de Polignac number, because 666216447045 - 2² = 666216447041 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666216447041) 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 15 ways as a sum of consecutive naturals, for example, 207542460 + ... + 207545669.

It is an arithmetic number, because the mean of its divisors is an integer number (67244277060).

Almost surely, 2^666216447045 is an apocalyptic number.

It is an amenable number.

666216447045 is a deficient number, since it is larger than the sum of its proper divisors (409691985915).

666216447045 is a wasteful number, since it uses less digits than its factorization.

666216447045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415088244.

The product of its (nonzero) digits is 5806080, while the sum is 51.

The spelling of 666216447045 in words is "six hundred sixty-six billion, two hundred sixteen million, four hundred forty-seven thousand, forty-five".