666166106663 has 4 divisors (see below), whose sum is σ = 666730177368. Its totient is φ = 665602035960.

The previous prime is 666166106647. The next prime is 666166106681. The reversal of 666166106663 is 366601661666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666166106663 - 2⁴ = 666166106647 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 (666166106863) 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, 282033581 + ... + 282035942.

It is an arithmetic number, because the mean of its divisors is an integer number (166682544342).

Almost surely, 2^666166106663 is an apocalyptic number.

666166106663 is a deficient number, since it is larger than the sum of its proper divisors (564070705).

666166106663 is a wasteful number, since it uses less digits than its factorization.

666166106663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564070704.

The product of its (nonzero) digits is 5038848, while the sum is 53.

The spelling of 666166106663 in words is "six hundred sixty-six billion, one hundred sixty-six million, one hundred six thousand, six hundred sixty-three".