666645445673 has 4 divisors (see below), whose sum is σ = 668386034688. Its totient is φ = 664904856660.

The previous prime is 666645445633. The next prime is 666645445693. The reversal of 666645445673 is 376544546666.

666645445673 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666645445673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666645445633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 870293933 + ... + 870294698.

It is an arithmetic number, because the mean of its divisors is an integer number (167096508672).

Almost surely, 2^666645445673 is an apocalyptic number.

It is an amenable number.

666645445673 is a deficient number, since it is larger than the sum of its proper divisors (1740589015).

666645445673 is a wasteful number, since it uses less digits than its factorization.

666645445673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740589014.

The product of its digits is 261273600, while the sum is 62.

The spelling of 666645445673 in words is "six hundred sixty-six billion, six hundred forty-five million, four hundred forty-five thousand, six hundred seventy-three".